Getting Started on International Law Research


This guide is intended to help you begin research on an international law topic at the Pritzker Legal Research Center. The guide focuses on secondary sources, such as books and journal articles, and the research tools, such as indexes, that can be used to identify such materials. Secondary sources can provide valuable background and analysis. They can also refer you to relevant documents, such as treaties, legislation, case law, or governmental documents. It is often best to start with secondary sources, especially for research in an unfamiliar area. The focus of this guide is on English language materials.

What is Public International Law? What is Private International Law?

A distinction is traditionally made between "public international law" and "private international law." In present day practice the distinction is not as sharply drawn as it may once have been. "Public international law" refers to relations between and among sovereign states, as well as international organizations. Some areas considered to fall within the purview of public international law are the law of war, the law of peace, the law of treaties, the law of state responsibility, international criminal law, and the international protection of human rights. Sometimes public international law is referred to simply as international law. The term "private international law" has been used in two ways. This term is used most frequently to refer to the area, known in the United States and some other common law countries as "conflict of laws," that encompasses issues--such as choice of law and choice of forum--that arise when a legal matter involves persons or other entities in different national jurisdictions. In this sense, private international law really refers to rules of domestic (national) law for dealing with such issues. There are various conventions in place to promote uniform practice in selected areas. For further discussion of this area, sometimes referred to as "international uniform law," see the excellent research guide Comparative Law by Paul Norman (GlobaLex). The term "private international law" is also used in some contexts to refer to legal transactions between individuals, businesses, etc. (entities other than states) in different national jurisdictions, in contradistinction to the traditional subject areas of public international law.

Some writers subsume the categories "foreign law" and "comparative law" under the category of "international law." For convenience this website maintains a separate section for Foreign and Comparative Legal Resources.

Modern day legal transactions may well involve matters of both domestic (national) law and international law. It is increasingly common for the terms "transnational" or "global" to be used to encompass all of the areas referred to above.

The "Sources" of International Law

Some further discussion of terminology may be helpful. One of the areas within the rubric of public international law is the "sources of international law." Scholarly treatments of the sources of international law are concerned with the question of what we look to in determining rules of international law. In this sense, the sources of international law (to simplify the frequently cited list found in the Statute of the International Court of Justice) are: conventions, international custom, and general principles of law. Judicial decisions and the teachings of "publicists" may also be looked to, but only as "subsidiary means" of determining international law. By analogy to common law, the first three of these (conventions, international custom, and general principles) are sometimes referred to as "primary" sources of international law, and the last two (judicial decisions and the teaching of "publicists") are sometimes referred to as "secondary" sources of international law. Click here for more detailed discussion of the sources of international law and for help in finding such materials.

However, in bibliographic resources, such as this "Getting Started" guide, the term "secondary sources" is used to refer to materials such as books, articles, and scholarly papers about international law subjects, irrespective of whether such materials rise to the level of "sources" of international law as discussed above.

Research Guides

One way to begin research is to consult a research guide on the subject. A research guide will usually include some substantive discussion, in addition to providing references to the major resources. Research guides are usually "annotated," i.e., each resource is described, not merely listed. Research guides that are available in electronic form usually link to the electronic resources that they cite. Note that some research guides in electronic form are limited to electronic resources and do not describe print resource that may be equally relevant.

  • Pratter, Jonathan, "Public International Law," in Fundamentals of Legal Research, by Steven M. Barkan, Barbara Bintliff, and Mary Whisner (10th ed., 2015.) pp. 433-489. Chapter 21 of this leading textbook on U. S. legal research is devoted to international legal research. MON KF240 .B268 2015
  • Germain, Claire. Germain's Transnational Law Research: A Guide for Attorneys
    A practice-oriented treatise. Excellent discussion of issues involved in transnational litigation. Chapters are devoted to researching specific topics, such as arbitration, banking, commercial law, intellectual property, and investments. Also includes chapters on European jurisdictions.
    I,REF K 85 .G47 1991-
  • Hoffman, Marci. International Legal Research in a Nutshell, by Marci Hoffman and Robert C. Berring (2008)
    I,MON KZ 1234 .H64 2008) (ON RESERVE)
  • Hoffman, Marci.  International and Foreign Legal Research: A Coursebook, by Marci Hoffman and Mary Rumsey (2d ed., 2012)
    I,REF K 85 .H64 2012
  • ASIL Guide to Electronic Resources for International Law, edited by Kelly Vinopal. (American Society of International Law). In addition to valuable general information on international law research, this guide provides detailed coverage of the following areas: Human Rights, International Commercial Arbitration, International Criminal Law, International Economic Law, International Environmental Law, Intellectual Property Law, International Organizations, Private International Law, Treaties, and United Nations.
  • GlobaLex (New York University School of Law) publishes research guides on various international law topics.
  • Our website includes research guides, when available, under its various subject areas: Criminal Law/War Crimes/Genocide | Environmental Law | Family Law | Human Rights | Intellectual Property | Trade, Business, and Economics Law | Terrorism | Treaties | Health | Sports

"Nutshells" on International Law Topics

One way to acquire substantive background on an unfamiliar subject is to consult a "Nutshell." "Nutshells" are paperback books published by Thomson/West. Each book in this series is devoted to a particular area of law and provides a concise explanation of the subject. A Nutshell can be an excellent introduction to a subject. Most Nutshells deal with areas of United States law, but a growing number cover international law topics.

  • Buergenthal, Thomas. Public International Law in a Nutshell, by Thomas Buergenthal and Sean D. Murphy (5th ed., 2013).
    I,MON KZ 3410 .B84 2013 (ON RESERVE)
  • Buergenthal, Thomas. International Human Rights in a Nutshell, by Thomas Buergenthal, Dinah Shelton, David P. Stewart (4th, 2009)
    I, MON K 3240.4 B84 2009 (ON RESERVE)
  • Folsom, Ralph H., et al. International Trade and Economic Relations in a Nutshell (5th ed., 2012)
    I,MON K 3943 .F64 2012 (ON RESERVE)
  • Folsom, Ralph H.,  International Business Transactions in a Nutshell, by Ralph H. Folsom (9th ed., 2012)
    I,MON K 3943 .F63 2012 (ON RESERVE)
  • Folsom, Ralph H. European Union Law in a Nutshell (8th ed., 2014)
    N,EAA KJE 949 .F55 2014 (ON RESERVE)
  • Guruswamy, Lakshman D. International Environmental Law in a Nutshell, by Lakshman D. Guruswamy with Maria Zebrowski Leach (4rd ed., 2012) I,MON K 3585.6 .G87 2012 (ON RESERVE)
  • Folsom, Ralph R. NAFTA and Free Trade in the Americas in a Nutshell (5th ed., 2014)
    N,KAA KDZ 944 .F653 2014 (ON RESERVE)

Treatises on International Law

Treatises provide in-depth, scholarly treatment of a subject. The following is a highly selective list.

Public International Law:

  • Malanczuk, Peter. Akehurst's Modern Introduction to International Law (7th rev. ed., 1997)
    I,MON JX 1308 .M35 1997
  • Brierly, J. L. The Law of Nations: An Introduction to the International Law of Peace (6th ed., 1963, ed. by Sir Humphrey Waldock)
    I,MON JX 3225 .B7 1963
  • Brownlie, Ian. Principles of Public International Law (7th ed., 2008)
    I,MON KZ 3225 .B76A37 2008
  • Cassese, Antonio. International Law (2nd ed., 2005)
    I,MON KZ 3395 .C25A35 2005
  • Oppenheim, L. Oppenheim's International Law (9th ed., 1992, ed. by Robert Jennings and Arthur Watts)
    I,MON JX 3264 .J6 1992 vol.1, pt. 1 and vol. 1, pt. 2-4
    Int 00 O621 1955 (Vol. 1, Peace; vol. 2, Disputes, War and Neutrality) and other older editions.
  • Rosenne, Shabtai. Practice and Methods of International Law (1984).
    This book, which discusses substantive aspects of public international law, is also useful as a research aid.
    I,MON JX 3695 .I8R67 1984
  • Schachter, Oscar. International Law in Theory and Practice (1991)
    I,MON JX 3091 .S264 1991
  • Starke, J. G. Starke's International Law (11th ed., 1994 / I.A. Shearer)
    I,MON JX 3295 .S8I48 1994
  • Verzijl, J.H.W. International Law in Historical Perspective (1968-1998)
    I,MON JX 3695 .D8V47 v. 1-12

International Trade, Business, and Economic Law:

  • Commentary on the UN Convention on the International Sale of Goods (CISG), ed. By Ingeborg Schwenzer (“Schlechtriem and Schwenzer”)(3rd ed., 2010)
    I,MON K 1028.3198 .A3K6613 2010
  • Honnold, John. Uniform Law for International Sales under the 1980 United Nations Convention (4th ed., 2009)
    I,MON K 1028.318 .H66 2009
  • Jackson, John H. The World Trading System: Law and Policy of International Economic Relations (2nd ed., 1997)
    I,MON K 4602.2 1997
    Also available electronically via netLibrary Available from anywhere to all members of the Northwestern University community.
  • Lowenfeld, Andreas F. International Economic Law (2nd ed., 2008).
    I,MON K 3941 .L69 2008

Encyclopedias and Dictionaries

Another way to obtain background information on a topic is to consult an encyclopedia or encyclopedic dictionary.

  • Max Planck Encyclopedia of Public International Law (online edition) Available from anywhere to all members of the Northwestern University community
    A comprehensive, scholarly work, still in the process of publication. This is a completely new edition of the Encyclopedia of Public international law (below).
  • Encyclopedia of Public International Law.
    Published under the auspices of the Max Planck Institute for Comparative Public Law and International Law. A highly regarded, scholarly encyclopedia. Its signed articles include bibliographic references.
    I ,REF JX 1226 .E52 1992 vols. 1-5
  • Osma&nczyk, Edmund Jan. Encyclopedia of the United Nations and International Agreements (3rd ed., 2003). Edited and revised by Anthony Mango.
    A four volume encyclopedia, broader in scope than its title indicates. Reprints the texts of many international agreements.
    I,REF KZ 4968 .O84 2003 vols. 1-4
  • Parry and Grant Encyclopaedic Dictionary of International Law (3rd ed. 2009). Edited by John P. Grant and J. Craig Barker. A one-volume work, with short entries.
    I,REF KZ 1161 .P37 2009 Also available electronically.

Finding Books (and Other Materials) on an International Law Topic

To find books at Northwestern University, search NUsearch, the catalog for the library's system. For instructions on searching NUsearch effectively, click here.

To identify books held by other library systems, use WorldCat.

Also see our page Find Books, Dissertations, and Other Monographs

Finding Articles on an International Law Topic

Articles provide background and analysis, and may supply citations to relevant primary sources.
  • To identify articles on a topic, use periodical indexes/databases. See the link below.
  • Typical citation will include name of the author, title of the article, abbreviation standing for name of periodical, and volume, year, and page. Abbreviation key may be included.
  • Some databases link to full text of articles. Some provide citations only. The "Find It At NU" button will lead to electronic fulltext if available to members of Northwestern University community or will suggest checking NUsearch for print edition if electronic version is not available.
  • The systematic way to access a journal at Northwestern, in print format or electronically, is to search for the title of the journal in NUsearch. Do a "journal title" search or a "title" search (if it is not clear that the cited source is a journal).
  • Some indexes are available in both electronic and print format. The print and electronic versions may vary in their coverage.
  • Some indexes used for international law research are also used for researching topics in United States law.
  • There is no one index that is comprehensive for international law. It is necessary to consult more than one index in order to do a thorough search.

Click here for a list of important periodical indexes for international law research

Internet Resources for International Law

A very large number of Internet sites are relevant to international law research. These include websites of international organizations (IGOs or NGOs, government agencies, and private organizations). There are subject-oriented sites, such as the human rights web site of the University of Minnesota Law Library; sites devoted to a particular type of material, such as the treaties site at the Fletcher School of Law and Diplomacy; and sites covering a broad selection of topics and materials.

At present our web site has sections for the following: Courts and Tribunals | Criminal Law/War Crimes/Genocide | Environmental Law | European Union | Family Law | Human Rights | Intellectual Property | International Organizations | Trade, Business, and Economic Law | Terrorism | Treaties | United Nations

Finding Documents

  • EISIL (Electronic Information System for International Law) (American Society of International Law) is a database of authenticated materials freely available on the Web. Note that EISIL does not link to subscription databases, such as the United Nations Treaty Collection. But a citation to the United Nations Treaty Series (UNTS), when available, may be obtained by clicking the "more information" link for a document and looking for the "Legal Citation."
  • HeinOnline Available from anywhere to all members of the Northwestern University community is a fee-based, searchable database that includes journal articles and many other materials in PDF. Sections relevant to international law include: International and Non-U.S. Law Journals; Foreign and International Law Resources Database; Foreign Relations of the United States; Kluwer Law International Journal Library; Philip C. Jessup Library; Treaties And Agreements Library; United Nations Law Collection (has United Nations Treaty Series searchable by U.N.T.S. citation).
  • The web sites of international organizations are often the most comprehensive and current sources for documents of the organization.
  • The library holds hard copy resources for various international organizations, such as the European Union, the Council of Europe, and the United Nations. For assistance please contact: Library Reference, Foreign, Comparative, and International Law Librarian (e-mail | (312) 503-8451)

Current Awareness and Topic Selection Aids

A number of resources are helpful for helping you select a current topic, and for updating your research. See the page Some Current Awareness Sources for International Law

Identifying Abbreviations

Click here for some helpful resources in identifying abbreviations and acronyms encountered in international law research.

 Barbara Bintliff
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