If you are new to the subject area that you are researching, including international law, set aside some time to develop a general understanding of your topic by skimming an encyclopedia or treatise. See George Washington Law School International Review, Guide to International Research at section (LexisNexis, 2018). The University of Detroit Mercy Law Library offers several good treatises on international law including:
You should also make sure that you are familiar with terminology that is basic to your area of inquiry.
Once you have a good grasp of your subject area, you'll need to start locating documents that speak to your specific issue. Id. Good general (nonofficial) resources might start you off in Lexis Advance, Westlaw, and HeinOnline.
The Electronic Information System for International Law (www.eisil.org) is a comprehensive free database created by the American Society of International Law (ASIL). EISIL is an "open database of authenticated primary and other materials across the breadth of international law, which until now have been scattered in libraries, archives and specialized web sites." ASIL, About EISIL (2008). Last retrieved on March 11, 2019, from the EISIL website.
Article 38 (1) of the International Court of Justice Statute provides:
The Court, whose function is to decide in accordance with international law such disputes as are submitted to it, shall apply: (a) international conventions, whether general or particular, establishing rules expressly recognized by the contesting states; (b) international custom, as evidence of a general practice accepted as law; (c) the general principles of law recognized by civilized nations; (d) subject to the provisions of Article 59, judicial decisions and the teachings of the most highly qualified publicists of the various nations, as subsidiary means for the determination of rules of law.
Sam Blay, Ryszard Piotrowicz, and B. Martin Tsamenyi (Eds.), Public International Law: an Australian Perspective (Oxford, 1997). Call No. KZ4735.P82 1997.
Barry E. Carter, Phillip R. Trimble, Allen S. Weiner, International law (Aspen Publishers, 2007). Call No. KZ1242.5.C37 2007.
B.S. Chimni, International Law and World Order: Critique of Contemporary Approaches (Sage, 1993). Call No. JX3091 .C55 1993.
John H. Currie, Public International law (Irwin Law, 2001). Call No. KZ3410.C87 2001.
James R. Fox, Dictionary of International and Comparative Law (Oceana Publications, 1997). Call No. KZ1161 .F69 1997.
Richard K. Gardiner,International Law (Longman, 2003). Call No. KZ3210 .G37 2003.
George Washington Law School International Review, Guide to International Research (LexisNexis, 2008). Call No. KZ1234.G85 2008.
John P. Grant and J. Craig Barker (eds). Parry and Grant Encyclopaedic Dictionary of International Law (2nd ed. 2004). Call No. KZ1161 .P37 2004.
A Guide to the United States Treaties in Force (Ed. Kavass, W.S. Hein Co., 1982). Call No. JX236.5 .G84.(Use in conjunction with, supra, Treaties in Force).
Timothy Hillier, Sourcebook on Public International Law (Cavandish, 1998). Call No. KZ1255.H55 1998.
Simone-Marie Kleckner, Public International Law and International Organization: International Law Bibliography (Oceana, 1984). Call No. Z6461.C65 1984 v. 1, no. 2.
Monroe Leigh and Merritt R. Blakeslee (Eds.), National treaty law and practice: France, Germany, India, Switzerland, Thailand, United Kingdom (American Society of International Law, 1995). Call No. K3342 .N38 1995.
John Allphin Moore, Jr. and Jerry Pubantz, Encyclopedia of the United Nations (2008). Call No. KZ4968 .M66 2008.
Stuart Nagel (Ed.), Handbook of Golbal Legal Policy (Dekker, 2000). Call No. K561.H365 2000.
Edmund Jan Osmanczyk, Encyclopedia of the United Nations and International Agreements (2003). Call No. KZ4968 .O86 2003.
Max Plank Yearbook of United Nation's Law [electronic resource] 1997-.
Jerry Martin Rosenberg, Encyclopedia of the North American Free Trade Agreement, the New American Community, and Latin-American trade (Greenwood Press, 1995). Call No. HC94 .R668 1995.
Mark Sachleben, Human rights treaties: considering patterns of participation, 1948-2000 (Routledge, 2006). Call No. K3240 .S23 2006.
Ellen G. Schaffer and Randall J. Snyder, Contemporary Practice of Public International Law (Oceana, 19997). Call No. KZ1234.C66 1997.
Walter Simons, The Evolution of Public Law in Europe Since Grotius (W.S. Hein & Co., 2004). Call No. KZ3390.S66 A34 2004.
I.M. Sinclair, The Vienna Convention on the Law of Treaties (Manchester University Press, 1984). Call No. JX4165 .S55 1984.
United States Treaty Index (Ed. Kavass, W.S. Hein, 1991-). Call No. KZ235 .U58 1991.(Try looking here if treaty is not in force).
Thomas Weiss and Sam Daws (Eds.), The Oxford Handbook on the United Nations (New York: Oxford Press, 2008). Call No. JZ 4970.O93 2008.
Mark Weston Janis, International law (New York: Aspen Publishers, 2008). Call No. KZ3140.J36 A35 2008.
Selected Titles in International Law Periodicals--titles are available in print and generally available online through HeinOnline, Lexis Advance, or Westlaw.
American Journal of International Law
American University International Law Review
Berkeley Journal of International Law
Duke Journal of Comparative and International Law
Emory International Law Review
Florida Journal of International Law
Georgetown Journal of International Law
George Washington International Law Review
Harvard International Law Journal
International Law Bulletin
Michigan Journal of International Law
Michigan State International Law Review
Minnesota Journal of International Law
Moscow Journal of International Law
MSU-DCL Journal of International Law
Notre Dame International Law Journal
Pace International Law Review
Penn State International Law Review
Stanford Journal of International Law
UCLA Journal of International Law and Foreign Affairs
University of Pennsylvania Journal of International Law
Washington International Law Journal
Yale Journal of International Law
Daniel Gardner, Institutes of International Law: Public and Private, as Settled by the Supreme Court of the United States, and by Our Republic (Voorheis, 1860) [Electronic Resource: Making of Modern Law].
International Law Topics and Discussions, 1914 (GPO, 1915). Call No. D 208.207:14.
T.J. Lawrence, A Handbook of Public International Law (Macmillan, 1925) [Electronic Resource: Making of Modern Law].
Amos Hershey, The Essentials of International Public Law (MacMillan, 1912) [Electronic Resource: Making of Modern Law].
Max Sorensen (Ed.), Manual of Public International Law (St. Martin's, 1968). Call No. JX3091.M36 1968.
Thomas Walker, A Manual of Public International Law (Cambridge, 1895) [Electronic Resource: Making of Modern Law].
See Thomas H. Oehmke, Arbitrating International Claims -- at Home and Abroad, 81 Am.Jur. Trials section 1 (2003). Oemke provides a relatively comprehensive explanation of the differences between international arbitration and domestic arbitration pursuant to Chapter 1 of the Federal Arbitration Act (FAA).
Guide to foreign and international legal citations (New York University, School of Law, 2006). Call No. KF245.G85 2006.
Cardiff Index to Legal Abbreviations
University of Minnesota, Frequently-Cited Treaties and Other International Instruments (good for law review cite checking).