UPDATE: Researching International Tax Law
By Christopher C. Dykes
Chris Dykes is currently the Head of Public Services at the University of Houston Law Center’s O’Quinn Law Library. He received his Juris-Doctor from the University of Baltimore School of Law and LL.M. in Taxation from Villanova University School of Law. He also holds a B.A. in Political Science and M.S. in Information Sciences from The University of Tennessee. 
Table of Contents
- 1. Introduction
- 2. Primary Sources
- 2.1. Vienna Convention on the Law of Treaties
- 2.2. Model Tax Conventions
- 2.3. Tax Treaties
- 2.4. Customary International Law
- 2.5. General Principles of Law
- 3. Secondary Sources
- 4. Research Guides
- 5. Sources Consulted for this Article
This research guide, based on International Tax Law: A Legal Research Guide (Buffalo: Hein, 2011) by Christopher C. Dykes, is designed to provide a starting point for those interested in international tax research. This guide will focus on international tax law from the global perspective but will also list information and sources for those interested in U.S. international taxation. This research guide will also discuss model income tax conventions, tax treaties, customary international law, and general principles of law. Secondary sources such as selected treatises, practice guides, and journals as well as online sources and research guides will also be covered.
This convention was adopted May 22, 1969 and entered into force on January 27, 1980. It is important because it provides the standards for all treaties, including tax treaties. Today, it has been ratified by 96 nations and there are 45 signatories, but the United States (although a signatory) is among the nations that failed to ratify this convention. Many federal and state appellate courts consider the provisions related to treaty interpretation to be binding despite the fact that the U.S. Senate has never ratified the Vienna Convention.
These provide a starting point for tax treaty negotiations between nations. There are three major model conventions that one needs to be familiar with: Organisation for Economic Cooperation and Development (OECD) Model Tax Convention; United States Model Tax Convention; United Nations Model Tax Convention. These three models are not binding but are designed to make tax treaty negotiations easier and to avoid any complications for nations whose laws require ratification.
OECD Model Tax Convention on Income and on Capital (2014 full version, 2017 update, condensed version): The OECD began in 1961 replacing the Organisation for European Economic Co-operation (OECC) created in 1948. The organization today includes 33 nations (mostly developed European nations and the United States). This convention contains commentaries along with reservations from member nations and opposing positions taken from nonmember nations. The OECD model provides the basis for tax treaty negotiations for most developed nations, who either use the model convention as their starting point or adapt most or all of the provisions for their own model tax convention. The OECD recently updated the model tax convention in November 2017, with the condensed version of the latest update now available.
U.S. Model Income Tax Convention (U.S. Model Income Technical Explanation): The U.S Income Tax Convention provides the starting point for the United States in negotiating tax treaties and was originally published in 1981, with revisions made in 1996,2006, and 2016. It contains accompanying technical explanations and is used to ensure that any issues that could potentially complicate the ratification process in the Senate are disposed of during bilateral negotiations. The U.S. model is similar to the OECD model in most respects but differs regarding anti-discrimination provisions related to foreign taxpayers and it also targets the use of tax havens more aggressively.
U.N. Model Double Taxation Convention between Developed and Developing Countries: The United Nations model published in 1980 was designed to assist developing nations with respect to tax treaty negotiations. The U.N. model is similar to the OECD Model and contains some of the same provisions but there are some notable differences such as provisions with blank percentages facilitating greater flexibility in tax treaty negotiations and more of a focus on source based taxation as opposed to residence based taxation. The U.N. Model is substantially different from the U.S. Model because of less rigorous nondiscrimination policies as well as less emphasis on tax fraud and fiscal evasion.
Locating Model Tax Treaties: The model tax conventions can be easily located online via the free internet as well as from the following sources:
- Baker, Philip. Double Taxation Conventions: a Manual on the OECD Model Tax Convention on Income and on Capital. London: Sweet & Maxwell, 3rd ed., 2001-.
- Federal Tax Coordinator (FTC), Chapter O.New York: RIA, 2nd ed., 1977-. Chapter O contains both the U.S. and OECD Model Tax Conventions.
- OECD Committee on Fiscal Affairs. Model Tax Convention on Income and on Capital. Paris: Organisation for Economic Co-operation and Development, 2014-.
- OECD Committee on Fiscal Affairs. Model Tax Convention on Income and on Capital: Condensed Version, 21 November 2117. Paris: Organisation for Economic Co-operation and Development, 2017.
- Rhoades, Rufus von Thülen and Langer, Marshall J. Rhoades & Langer U.S. International Taxation and Tax Treaties. New York: Matthew Bender, 1996-. Contains the U.S. Model Tax Convention with technical explanations.
- Tax Treaties: Full Texts of U.S. Treaties with Foreign Countries Covering Income and Estate Taxes. Chicago: Wolters Kluwer/CCH, 1965-. This set has both the U.S. and OECD model tax conventions.
- Tittle, Martin B. & Avi-Yonah, Reuven S. The Integrated 2006 United States Model Income Tax Treaty. Lake Mary, FL: Vandeplas Publishing, 2008.
- Ward, David. The Interpretation of Income Tax Treaties with Particular Reference to the Commentaries on the OECD Model. Kingston, ON: International Fiscal Association (Canadian Branch); Amsterdam: International Bureau of Fiscal Documentation, 2005. Contains the OECD Model Tax Convention in the appendices.
Tax treaties are the most authoritative source of international tax law, but that authority is contingent upon how an individual nation views the terms of the treaty in relation to its domestic laws. Some countries view the treaties as automatically binding whereas other countries require special legislative procedures beyond simple ratification before the treaty’s provisions effectively become law. The United States in particular views tax treaties as “the supreme law of the land.” However if there is a conflicting statute such authority depends on whether the treaty was passed later than that statute.  Treaties that are passed later in time are more authoritative than those entered into beforehand.  Self-executing treaties (those with provisions that stipulate enforcement) have more force in most jurisdictions than non-self-executing treaties.
Tax treaties exist for the most part to avoid double taxation and prevent tax fraud or fiscal evasion.  Double taxation takes place when the taxpayer is taxed by the foreign nation of residence and the home country at the same time. For example, if a U.S. citizen were living abroad in Argentina, that person would not only be subject to taxation in that country but also the United States, regardless of residence. Double taxation is problematic because it can stifle commerce, discourage international trade, and can be particularly devastating to nations whose economies rely heavily on tourism. While double taxation can be crippling to all nations, tax evasion is a greater concern for developed nations than it is for developing nations because they are more likely to lose revenue. The expatriation of U.S. citizens to nations known as “tax havens” that boast little or no tax burden has been a problem in recent years.  While Congress has created restrictions designed to discourage this tactic through the enactment of the “Heroes Earnings Assistance and Relief Tax Act of 2008,” there are other maneuvers used to hide assets offshore that will continue to be a major issue in tax treaty negotiations. Tax treaties may also deal with other issues such as nondiscrimination against foreign nationals and the reduction of withholding rates. 
There are times when nations cannot agree upon a comprehensive tax treaty and as such will often enter into treaties or agreements that focus on one particular issue. These agreements often include those that protect social security payments from double taxation along with those that focus on tax exemptions and credits for transportation costs, sharing information between nations regarding a particular taxpayer, and double taxation and fraud as it relates to taxes on gifts, estates, and inheritances. The United States has agreements with a number of nations where negotiations for a comprehensive tax treaty have failed. These agreements are viewed as authoritative as ratified treaties from an international standpoint, and domestically, the Supreme Court has upheld the President’s authority to enter into such agreements. 
Locating U.S. Tax treaties is manageable because of the enormous number of commercial and noncommercial sources available that contain these treaties. Although there are noncommercial sources, commercial services are still important because of the analysis that they provide. Researching non-U.S. tax treaties is extremely difficult unless one has access to a database with the full text of tax treaties because fewer academic law libraries continue to subscribe to the print materials that contain them. The language barrier can also pose problems for those attempting to locate non-U.S. tax treaties from non-commercial sources, making databases with the English translation essential.
- Internal Revenue Bulletin (IRB). Washington: Internal Revenue Service, 1953-.: These were compiled biannually into the Cumulative Bulletin (CB) until the end of 2008. The I.R.S.gov website has Internal Revenue Bulletin issues from 1996 until current. Washington: Internal Revenue Service, 1922-.
- Treaties and Other International Acts Series (TIAS). Washington: U.S. Government Printing Office, 1946-.
- United States Treaties and other International Agreements (UST). Washington: U.S. Government Printing Office, 1950-.
- U.S. Congressional Set: Senate Executive Documents/Senate Treaty Documents. Washington: U.S. Government Printing Office, 1979-.
- Federal Tax Coordinator, Chapter O. New York: Thomson Reuters/RIA, 1977-.
- Rhoades, Rufus von Thülen and Langer, Marshall J. Rhoades and Langer. U.S. International Taxation and Tax Treaties. New York: Matthew Bender, 1996-.
- Tax Treaties: Full Texts of U.S. Treaties with Foreign Countries Covering Income and Estate Taxes. Chicago: CCH, 1965-.
Treaty Guides and Indexes:
- Kavass’s Guide to U.S. Treaties in Force. Buffalo, NY: W.S. Hein Co, 1982-.
- Kavass’s Guide to the United States Treaties in Force. Current Treaty Action Supplement. Buffalo, NY: W.S. Hein Co, 1994-.
- Kavass, Igor I. United States Treaty Index: 1776-2000 Consolidation. Buffalo, NY: W.S. Hein & Co, 1991-.
- Kavass’s Current Treaty Index. Buffalo, NY: W.S. Hein Co., 1982-.
- Treaties in Force: a List of Treaties and Other International Agreements of the United States. Washington: Government Printing Office, 1929-.
- Diamond, W.H. & Diamond, D.B. International Tax Treaties of all Nations. Dobbs Ferry, NY: Oceana Publications, 1975-; Series B, 1978-1997.
- United Nations Treaty Series (U.N.T.S.). New York: United Nations, 1947-.
For those matters not covered by tax treaties, customary international law can help by looking at the “relatively uniform and consistent state practice regarding a particular matter” to determine whether such action was taken based on the obligation or belief that it was legal based on international law. Customary international law will review past actions taken by nations with respect to tax related issues and evidence of such can be found through sources of state practice, digests, and yearbooks.
Sources of State Practice
- Foreign Law Guide, available exclusively online by subscription (Foreign Law Guide).
- Gaebler, Ralph & Smolka-Day, Maria, eds. Sources of State Practice in International Law. Ardsley, NY: Transnational Publishers, 2002-2005.
- Gaebler, Ralph & Shea, Alison, Sources of State Practice in International Law. (2d ed.) Leiden, The Netherlands ; Boston: Brill-Nijhoff, 2014.
- See Fundamentals of Legal Research  and Sources of State Practice in International Law for a more comprehensive listing of digests and yearbooks. The titles listed below are available through the HeinOnline database.
- Digest of United States Practice in International Law (annual). Guymon, Carrie Lyn D., ed. Washington, DC: U.S. State Department, 2011-2017
- Cumulative Digest of United States Practice in International Law. Nash, Marian Lloyd, ed. Washington, DC: U.S. State Department, 1993-1995 (covers 1981-1988).
- Digest of United States Practice in International Law (annual). Washington: International Law Institute. Oxford University Press, 2001 (covering 1989-2008, materials from 1989-1999 are incomplete and are currently being published) (cumulative index available).
- Digest of United States Practice in International Law. Rovine, Arthur W., McDowell, Eleanor C., Boyd, John A. & Nash, Marian Lloyd, eds. Washington: U.S. State Department, 1973-1980 (cumulative index available).
For matters that cannot be determined by treaties or customary international law, general principles of law can provide guidance to attorneys who are handling issues with little or no legal precedence. These are basic legal concepts that are imperative to all nations and involve matters not readily dealt with by treaties. The authority of general principles of law has been given credibility by the Statute of the International Court of Justice requiring the court to consider, after consulting treaties and customary international law, “the general principles of law recognized by civilized nations” in determining the outcome of cases. General principles of law can be established by looking at case law and scholarly works.
The following is a list of sources that can used to ascertain general principles of law:
- Crawford, James. Ian Brownlie’s Principles of Public International Law, 8th ed. Oxford: Oxford University Press, 2012.
- Cheng, Bin. General Principles of Law, as Applied by International Courts and Tribunals. London: Stevens, 1953. Reprinted, Cambridge; New York: Cambridge University Press, 2006.
- International Court of Justice (ICJ)
- International Criminal Court
- International Law in Domestic Courts
- International Legal Materials (ILM). Washington: American Society of International Law (ASIL), 1962-.
- Raimondo, Fabián O. General Principles of Law in the Decisions of International Criminal Courts and Tribunals. Leiden, Netherlands; Boston: M. Nijhoff Publishers, 2008.
- Tax Treaty Case Law Around the Globe. Amsterdam, Netherlands: IBFD, 2017.
- WorldLII International Courts and Tribunals
There are numerous secondary sources that focus on international tax law and these are important because they provide analysis that is fundamental for those who practice or research in this area. Keep in mind that the vast majority of materials focus on international taxation from a U.S. practitioner point of view while fewer sources view international taxation from a global perspective.
- Diamond, Walter H. & Diamond, Dorothy B. Tax Havens of the World. New York: LexisNexis, 1981-.
- Herzfeld, Mindy & Doernberg, Richard L. International Taxation in a Nutshell 11th ed. St. Paul: West Academic Publishing, 2018.
- Isenbergh, Joseph. International Taxation, 3rd ed. New York: Foundation Press/Thomson Reuters, 2010.
- Isenbergh, Joseph. International Taxation: U.S. Taxation of Foreign Persons and Foreign Income, 5th ed.
- Riverwoods, IL : Wolters Kluwer, , 2017-.
- Kleinfeld, Denis A. & Smith, Edward J. Langer on Practical International Tax Planning, 4th ed. New York: Practicing Law Institute, 2000-.
- Lawrence, Robert C. International Tax and Estate Planning: a Practical Guide for Multinational Investors, 3rd ed. New York: Practising Law Institute, 1996-.
- Levey, Marc M. & Wrappe, Steven C. Transfer Pricing: Rules, Compliance and Controversy, 4th ed. Chicago: CCH, 2013.
- Postlewaite, Philip F. & Wiess, Mitchell B. International Taxation: Corporate and Individual, 10thed. 2 vols.Durham, North Carolina: Carolina Academic Press, 2016.
- Schadewald, Michael S. & Misey, Robert J. Practical Guide to U.S. Taxation of International Transactions, 11th ed. Riverwoods, IL: Wolters Kluwer, 2018.
- Tax Management Portfolios. Washington: Bloomberg BNA, 1971-.: Bloomberg BNA publishes a collection of mini-treatises that explore a number of tax topics related to U.S. Income Tax, Trusts and Estates, State Tax, Accounting, Sales and Use, and Foreign and International Tax. They summarize the law, contain examples, and include sample forms. The portfolios that focus on business operations abroad are among the most helpful for the U.S. practitioner because they explore the tax issues that pertain to the U.S. and another specific country. These are available in print and online through the Bloomberg BNA tax and accounting database and BloombergLaw.com.
- Thompson, Samuel C. U.S. International Tax Planning and Policy: Including Cross-Border Mergers and Acquisitions, 2nd ed. Durham, NC: Carolina Academic Press, 2016.
- Warren, Gorham & Lamont (WG&L) Series (available on Westlaw, Thomson Reuters Checkpoint)
- Anderson, Richard. Analysis of United States Income Tax Treaties, 2018.
- Anderson, Richard. Foreign Tax Credits, 2018.
- Bittker, Boris & Lokken, Lawrence. Federal Taxation of Income, Estates and Gifts, 3rd ed., 2018.
- Bittker, Boris & Lokken, Lawrence. Fundamentals of International Taxation: U.S. Taxation of Foreign Income and Foreign Taxpayers, 2018.
- Conlon, Steven D. & Aquilino, Vincent M. Principles of Financial Derivatives: U.S. and International Taxation, 1999-.
- Dolan, D. Kevin,Jackman, Patrick, Tretiak, Philip & Dabrowski, Ronald. U.S. Taxation of International Mergers, Acquisitions, and Joint Ventures, 19952018.
- Lowell, Cym, Martin, Mark & Levey, Marc. &. International Transfer Pricing: OECD Guidelines, 2018.
- Kuntz, Joel D. & Peroni, Robert J. U.S. International Taxation, 1991-.
- Levey, Marc. U.S. Taxation of Foreign Controlled Businesses, Valhalla, NY: Thomson Reuters/WG&L, 2010.
- Lowell, Cym H. & Martin, Mark R. U.S. International Transfer Pricing, 2018.
- Lowell, Cym H. & Martin, Mark R. U.S. International Taxation: Practice and Procedure, 2018.
- Lowell, Cym H. & Martin, Mark R. U.S. International Taxation: Agreements, Checklists & Commentary, 2018.
- Michaels, Marnin J. International Taxation: Withholding, 2018.
- Spielman, Michael. U.S. International Estate Planning, 2018.
- Tilton, G. Michael. U.S. International Tax Forms Manual: Compliance and Reporting, 2018.
- Avi-Yonah, Reuven S. Advanced Introduction to International Law. Northampton, MA: Edward Elgar, 2016.
- Avi-Yonah, Reuven S. International Tax as International Law: An Analysis of the International Tax Regime. Cambridge Tax Law Series. New York: Cambridge University Press, 2007.
- Ault, Hugh J. & Arnold, Brian J. Comparative Income Taxation: a Structural Analysis, 3rd ed. Alphen aan den Rijn. Netherlands: Kluwer Law International distributed in North America by Aspen Publishers, 2010.
- Basu, Subhajit. Global Perspectives on E-Commerce Taxation Law. Burlington, VT: Ashgate Publishing Company, 2007.
- Fundamentals of International Tax Planning. Russo, Raffeale, ed. Amsterdam: IBFD, 2007.
- Holmes, Kevin. International Tax Policy and Double Tax Treaties: an Introduction to Principles and Application, 2d ed. Amsterdam: IBFD, 2014.
- IBFD Doctoral Series (Volumes 1-30)
- The International Bureau of Fiscal Documentation (IBFD) publishes a series of dissertations that explore tax issues from the global perspective.
- Holmes, Dr. Kevin. Vol. 1: The Concept of Income: A Multi-Disciplinary Analysis, 2001.
- Herman, Dr. Doran. Vol. 2: Taxing Portfolio Income in Global Financial Markets, 2002.
- Thiel, Prof. Servaas van. Vol. 3: Free Movement of Persons and Income Tax Law: the European Court in Search of Principles , 2002.
- Romano, Dr. Carlo. Vol. 4: Advance Tax Rulings and Principles of Law, 2002.
- Züger, Dr. Mario. Vol. 5: Arbitration under Tax Treaties, 2001.
- Pinto, Dr. Dale. Vol. 6: E-Commerce and Source-Based Income Taxation, 2003.
- Engelen, Frank. Vol. 7: Interpretation of Tax Treaties under International Law, 2004.
- Vitala, Dr. Tomi. Vol. 8: Taxation of Investment Funds in the European Union, 2005.
- Barenfeld, Dr. Jesper. Vol. 9: Taxation of Cross-Border Partnerships, 2005.
- Molenaar, Dr. Dick. Vol. 10: Taxation of International Performing Artistes, 2006.
- Altman, Dr. Zvi. Daniel. Vol. 11: Dispute Resolution under Tax Treaties, 2006.
- Pötgens, Frank. Vol. 12: Income from International Private Employment, 2007.
- Laukkanen, Antti. Vol. 13: Taxation of Investment Derivatives, 2007.
- De Broe, Luc. Vol. 14: International Tax Planning and Prevention of Abuse, 2008.
- Fibbe, Gijs. Vol. 15: EC Law Aspects of Hybrid Entities, 2009.
- De la Feria, Rita. Vol. 16: EU VAT System and the Internal Market, 2009.
- Mayer, Stefan. Vol. 17: Formulary Apportionment for the Internal Market, 2009.
- Rendahl, Pernilla. Vol. 18: Cross-Border Consumption Taxation of Digital Supplies, 2009.
- Isenbaert, Dr. Mathieu. Vol. 19: EC Law and the Sovereignty of the Member States in Direct Taxation, 2010.
- Bullen, Dr. Andreas. Vol. 20: Arm's Length Transaction Structures - Recognizing and Restructuring Controlled Transactions in Transfer Pricing, 2011.
- Douma, Sjoerd. Vol. 21: Optimization of Tax Sovereignty and Free Movement, 2011.
- Monsenego, Jerome. Vol. 22: Taxation of Foreign Business Income within the European Internal Market, 2012.
- Wheeler, Joanna. Vol. 23: The Missing Keystone of Income Tax Treaties, 2012.
- Bammens, Niels. Vol. 24: The Principle of Non-Discrimination in International and European Tax Law, 2013.
- Ecker, Thomas. Vol. 25: A VAT/GST Model Convention, 2013.
- Farrell, Jennifer E. Vol. 26: The Interface of International Trade Law and Taxation, 2013.
- Schaper, Marcel. Vol. 27: The Structure and Organization of EU Law in the Field of Direct Taxes, 2013.
- Perrou, Katerina. Vol. 28: Taxpayer Participation in Tax Treaty Dispute Resolution, 2014.
- Fett, Dr. Emily. Vol. 29: Triangular Cases: The Application of Bilateral Income Tax Treaties in Multilateral Situations, 2014.
- Tetlak, Karolina. Vol. 30: Taxation of International Sportsmen, 2014.
- Peters, Cees. Vol. 31: On the Legitimacy of International Tax Law, 2014.
- Szudoczky, Rita. Vol. 32: The Sources of EU Law and Their Relationships: Lessons for the Field of Taxation, 2014.
- Arginelli, Paolo. Vol. 33: Multilingual Tax Treaties: Interpretation, Semantic Analysis and Legal Theory, 2015.
- Pfeiffer, Sebastian. Vol. 34: VAT Grouping from a European Perspective, 2015.
- Slavnić, Nana Šumrada. Vol. 35: European Capital Movements and Corporate Taxation, 2015.
- Lamensch, Marie. Vol. 36: European Value Added Tax in the Digital Era, 2015.
- Miller, Angharad. Vol. 37: Taxing Cross-Border Services: Current Worldwide Practices and the Need for Change, 2016.
- Bronżewska,Katarzyna. Vol. 38: Cooperative Compliance: A New Approach to Managing Taxpayer Relations, 2016.
- Souza de Man, Fernando, Vol. 39: Taxation of Services in Treaties between Developed and Developing Countries, 2017.
- Navarro, Aitor. Vol. 40: Transactional Adjustments in Transfer Pricing, 2018.
- Gadžo, Stjepan. Vol. 41: Nexus Requirements for Taxation of Non-Residents’ Business Income, 2018.
- Pit, Harm Mark. Vol. 42: Dispute Resolution in the EU, 2018.
- Furuseth, Eivind. Vol. 43: The Interpretation of Tax Treaties in Relation to Domestic GAARs, 2018.
- Li, Na. Vol. 44: The Tax Spring Mechanism and Foreign Direct Investment, 2018.
- Torvik, Oddleif. Vol. 45: Transfer Pricing and Intangibles: US and OECD Arm’s Length Distribution of Operating Profits from IP Value Chains, 2018.
- Kollmann, Jasmin. Vol. 46: Taxable Supplies and Their Consideration in European VAT: With Selected Examples of the Digital Economy, 2018.
- International Tax Law, 2nd ed.Amatucci, Andrea, ed. Frederick, MD: Kluwer Law International, distributed in North America by Aspen Publishers, 2012.
- International Tax Law. Avi-Yonah, Reuven S., ed. 2 vols.nutsNorthampton, MA: Edward Elgar, 2016.
- Koele, Ineke Alein. International Taxation of Philanthropy: Removing Tax Obstacles for International Charities. Amsterdam: IBFD, 2007.
- Lang, Michael. Introduction to the Law of Double Taxation Conventions, 2d ed. Amsterdam: IBFD, 2013.
- Materials on International, TP & EC Law, 17th ed. Vols. A, B, & C. Raad, Kees Van, ed. Leiden, Netherlands: International Tax Center, 2018.
- Roy Rohatgi on International Taxation - Volume 1: Principles. Ostaszewska, Ola & Obuoforibo, Belema,eds. Amsterdam: IBFD, 2018.
- International Tax Monitor. Washington: Bloomberg BNA, 2001-.
- Tax Notes International. Arlington, VA: Tax Analysts, 1989-.
- Worldwide Tax Daily. Arlington, VA: Tax Analysts, 1998-.
- Berkeley Journal of International Law. Berkeley: University of California Press, 1996- (previously International Tax and Business Lawyer, 1983-1996).
- Bulletin for International Taxation. Amsterdam: IBFD, 2006-.
- International Tax Journal.Greenvale, NY: Panel Publishers, 1974-.
- Journal of Taxation of Global Transactions. Chicago: Commerce Clearing House (CCH), 2001-2006 (merged with International Tax Journal starting 2007).
- Tax Management International Journal. Washington, DC: Bureau of National Affairs. Tax Management Inc., 1972-.
- World Tax Journal. Amsterdam: IBFD, 2009-.
- IBFD International Tax Glossary, 7th ed. Rogers-Glabush, Julie, ed. Amsterdam, Netherlands: IBFD, 2015.
- Smith, Robert Sellers. West’s Tax Law Dictionary. St. Paul, MN: Thomson/West, 2018 (available on Westlaw).
- Westin, Richard. Tax Dictionary. Valhalla, NY: Thomson Reuters/WG&L, 2014 (available on Thomson Reuters Checkpoint).
Online research is essential for international tax research particularly for those who need to access tax treaties and model tax conventions. There are a number of free databases provided by the U.S. government as well as foreign and international agencies but access to subscription databases are imperative for those who need to locate non-U.S. tax treaties.
U.S. Government Agency Websites
- Government Publishing FDSys: Contains select treaties pending before the U.S. Senate from 1995 to present.
- IRS: Provides access to the full text of U.S. income tax treaties and the model U.S. income tax treaty and technical explanations.
- Joint Committee on Taxation: The Joint Committee on Taxation, a non-partisan congressional committee reports to the U.S. Senate Foreign Relations Committee regarding pending U.S. tax treaties and makes the technical explanations of such treaties available on its website.
- U.S. State Department Treaty Affairs: Has Treaties and International Acts Series (TIAS, 1996-2014), the most recent Treaties in Force (TIF), Treaty Actions (individual states’ actions on treaties), and a current list of treaties pending before the U.S. Senate.
- U.S. Department of Treasury, Office of Tax Policy: Contains transcripts of congressional testimony, reports to Congress, guidance, and the full text of tax treaties for select countries with analysis from the Joint Committee on Taxation.
Foreign and International Agency Websites
- European Union (EUROPA) - Official site of the European Union contains case law from the European Union Court of Justice and treaties.
- Organisation for Economic Cooperation and Development (OECD) - This site contains the OECD legal instruments database allowing users to search international agreements, understandings and declarations, and decisions from OECD committees known as “the OECD Acts.”
- World Trade Organization - Provides access to tariff and trade statistics and both the 1947 and 1994 versions of the General Agreement on Tariffs and Trade (GATT).
- United Nations, UNTS - Provides access to deposited treaties including non-U.S. tax treaties.
- Bloomberg Law - Provides access to U.S. tax treaties and agreements, news and commentary, and over 500 tax management portfolios covering topics related to U.S. Income, Estates, Gift, and Trust, Foreign and International Tax (from the U.S. practitioner perspective), State Tax, Sales and Use Tax, and Accounting
- International Bureau of Fiscal Documentation (IBFD) - The IBFD Tax Research Platform contains U.S. and non-tax treaties in both the native language and English, U.S. and U.N. model conventions, Tax Treaty Case Law, which interprets tax treaties, Tax Glossary, and Tax News Service, among other sources.
- HeinOnline - Contains Treaties and Agreements library, which provides access to treaties from U.S. Statutes at Large, U.S. Treaties and other International Agreements (UST, 1950-1984), Treaties and International Acts Series, (TIAS, 1982-2018), Treaties in Force (TIF, 1929-2018), Treaty guides and indexes, U.S. Digest Series, Executive Agreement Series, Senate treaty document series, and yearbooks.
- Cheetah (CCH) - Contains U.S. and non-U.S. tax treaties, all three-model tax conventions, and a number of treatises such as Klaus Vogel on Double Taxation Conventions and Pasquale Pistone’s the Impact of Community Law on Tax Treaties-Issues and Solutions.
- Lexis Advance - U.S. tax treaties and agreements from Rhoades and Langer Tax Treaties and non-U.S. tax treaties from Tax Analysts Worldwide Tax Treaties, news and current awareness from Tax Analysts Worldwide Tax Daily, and a number of treatises and practice guides such as International Tax and Estate Planning, Double Taxation Relief, and Tax Havens of the World.
- TaxNotes.com - Worldwide Tax Treaties has all types of U.S. and non-U.S. tax treaties in the native language and English and features a quick treaty locator tool and a feature that allows up to three treaties to be viewed side-by-side. The full text of the OECD model tax convention is available. This platform provides other current awareness sources, most notably Tax Notes Today, State Tax Today, and Worldwide Tax Daily, which provides foreign and international tax news.
- Thomson Reuters Checkpoint - U.S. tax treaties and explanations and non-U.S. tax treaties from IBFD (requiring a special subscription) are available. The Warren, Gorham, and Lamont (WG&L) treatises including those focusing on foreign and international tax are available such as Anderson: Analysis of United States Income Tax Treaties, Anderson: Foreign Tax Credits, and Kuntz & Peroni: U.S. Taxation of Foreign-Controlled Businesses.
- Westlaw - RIA materials from Thomson Reuters Checkpoint are available depending on subscription such as RIA International Tax Treaties and Explanations, and WG&L Combined International Tax Treaties, along with many WG&L treatises that focus on foreign and international tax from a U.S. practitioner standpoint.
There are a number of research guides compiled by academic law libraries on the subject of international taxation:
- Depaul College of Law Library
- Georgetown Law Library
- Suffolk University Law School, John Joseph Moakley Law Library
- Ault, Hugh J. Reflections on the Role of the OECD in Developing International Tax Norms, 34 Brook. J. Int’L L. 757 (2009).
- Barkan, Steven M., Mersky, Roy M. & Dunn, Donald J. Fundamentals of Legal Research, 9th ed. New York: Foundation Press, 2009.
- Bittker, Boris & Lokken, Lawrence. Federal Taxation of Income, Estates, and Gifts, 3rd ed. Boston: Warren, Gorham & Lamont, 1999-.
- Brownlie, Ian. Principles of Public International Law, 7th ed. Oxford: Oxford University Press, 2008.
- Chemerinsky, Erwin. Constitutional Law: Principles and Policies, 4th ed. New York: Aspen Publishers, 2011.
- Criddle, Evan J. The Vienna Convention on the Law of Treaties in U.S. Treaty Interpretation. 44 Va. J. Int’l. L. 431 (2004)
- Dykes, Christopher. International Tax Law: A Legal Research Guide. Buffalo: Hein, 2011.
- Fundamentals of International Tax Planning. Russo, Raffeale, ed. Amsterdam: IBFD, 2007.
- Herzfeld, Mindy & Doernberg, Richard L. International Taxation in a Nutshell 11th ed. St. Paul: West Academic Publishing, 2018.
- Hoffman, Marci B. & Berring, Robert C. International Legal Research in a Nutshel, l2nd ed. St. Paul: West Academic Publishing, 2017.
- International Tax Law. 2nd ed. Andrea Amatucci, ed. Frederick, MD: Kluwer Law International, distributed in North America by Aspen Publishers, 2014.
- Isenbergh, Joseph. International Taxation, 3rd ed. New York: Foundation Press/Thomson Reuters, 2010.
- Janis, Mark W. An Introduction to International Law, 5th ed. New York: Aspen Publishers, 2008.
- Murphy, Sean D. Principles of International Law, 2nd ed. St. Paul, MN: Thomson West, 2018.
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- Rohatgi, Roy. Basic International Taxation, 2d ed.: Volume 1: Principles. Richmond, UK: Richmond Law & Tax Ltd., 2005.
- Rotunda, Ronald D. & Nowak, John E. Treatise on Constitutional Law-Substance & Procedure, 5th ed. St. Paul, MN: Thomson/West, 2017.
- Statute of the International Court of Justice, June 26, 1945, 59 Stat. 1055, 3 Bevans 1179.
- U.N. Dep’t of Econ. & Soc. Affairs, United Nations Model Double Taxation Convention between Developed and Developing Countries. U.N. Doc. ST/ESA/PAD/SER.E/21, U.N. Sales No. E.01.XVI.2 (2001).
- United States Model Income Tax Convention of February 17, 2016 and its Preamble
- United States Model Technical Explanation Accompanying the United States Model Income Tax Convention of November 15, 2006.
 Special thanks to the following for their assistance and support: Amanda Watson, Director and Assistant Professor of Law at the University of Houston Law Center, O’Quinn Law Library; Emily Lawson , Associate Director of the University of Houston Law Center, O’Quinn Law Library; and Dan Baker, Reference Librarian at the Capital University Law Library, O’Quinn Law Library.
 Vienna Convention on the Law of Treaties, May 23, 1969, 1155 U.N.T.S. 331
1 Roy Rohatgi, Basic International Taxation, §2.2.1, at 27 (2d ed. 2005).
 See Evan J. Criddle, The Vienna Convention on the Law of Treaties in U.S. Treaty Interpretation, 44 Va. J. Int’l, L., 431, 433-434 (2004).
 Model Convention with Respect to Taxes on Income and on Capital, as of July 15, 2014, reprinted in OECD Committee on Fiscal Affairs, Model Tax Convention on Income and on Capital—Condensed Version (2014).
 U.N. Dep’t of Econ. & Soc. Affairs, United Nations Model Double Taxation Convention between Developed and Developing Countries, U.N. Doc. ST/ESA/PAD/SER.E/21, U.N. Sales No. E.01.XVI.2 (2001) hereinafter U.N. Model Tax Convention.
 See Hugh J. Ault, Reflections on the Role of the OECD in Developing International Tax Norms, 34 Brook. J. Int’L. L. 757, 758 (2009).
 See U.S. Model Income Tax Convention, art. 24; Joseph Isenbergh, International Taxation 224-225 (3rd ed. 2010).
 See U.N. Model Tax Convention, supra note 8, Introduction 2, at vii, 10, at x-xi.
 See Rohatgi, supra Note 3, §3.2.1, at 104.
 See Mark W. Janis, An Introduction to International Law 100-105(5th ed. 2008).
 U.S. Const. art. VI, cl. 2.
 See 1 Ronald D. Rotunda & John E. Nowak, Treatise on Constitutional Law-Substance & Procedure 6.7(a) (5th ed. 2017).
 International Tax Law 164-166 (Andrea Amatucci ed., 2012).
 See Boris Bittker & Lawrence Loken, Federal Taxation on Income, Estates, and Gifts 66.1A.2 (2 Cum. Supp. 2018).).
 Pub. L. 110-245, 122 Stat. 1624 (2008).
 See International Tax Law supra note 18, at 166-168.
 See e.g., United States v. Pink, 315 U.S. 203 (1942); United States v. Belmont, 301 U.S. 324 (1937); Dames & Moore v. Regan, 453 U.S. 654 (1981). See Erwin Chemerinsky, Constitutional Law: Principles and Policies §§ 3.5.1 (4th ed., 2011).
 Sean Murphy, Principles of International Law 93 (2012).
 Id. at 94-95.
 Steven M. Barkan, Roy M. Mersky & Donald J. Dunn, Fundamentals of Legal Research 440-42 (9th ed. 2009).
 See Janis, supra note 14, at 58.
 Id.; Statute of the International Court of Justice, art. 38(1)(b), June 26, 1945, 59 Stat. 1055, 3 Bevans 1179, hereinafter Statute of the ICJ.
 Statute of the ICJ, supra note 27, art. 38(1)(c); See Marci B. Hoffman & Robert C. Berring, International Legal Research in a Nutshell, 2nd ed. 81-85 (2017) for a detailed explanation on the general principles of law.