Customary International Law, General Principles of Law, and Other Sources

Research Guides & Background Information

Background Information

Department of State

Research Guides & Background Information


Domestic Law Concerning a Country's International Obligations

Resolutions, Declarations, and Legislative Acts of Intergovernmental

IGO yearbooks


Judicial Decisions of
International Tribunals

Court Decisions of Individual Countries Concerning International Obligations

Scholarly Works

Review Questions

Domestic Legislation Concerning a Country's International Obligations

Sometimes a country’s legislation (session and statutory laws) provide evidence of international custom. Probably the best source for finding the laws of other countries is Thomas A. Reynolds and Arturo A. Flores, Foreign Law: Current Sources of Codes and Legislation in Jurisdictions of the World (the electronic version, Foreign Law Guide is available by subscription at many law school libraries).

Another good resource is the Martindale-Hubbell International Law Digest which includes summaries of the law on specific subjects for about 60 countries with citations to sources; it is also available in the subscription databases LexisNexis (MARHUB;INTDIG).

Foreign and International Law Resources: An Annotated Guide to Web Sites Around the World and the Library of Congress’s Nations of the World provide links to legislation on the web arranged by country. Some legislation is available in the subscription databases Lexis and Westlaw; see the database directories for more information.

National gazettes, official publications that print laws, regulations, and other legal documents, are good sources of legislation for some countries. John E. Robert, Guide to Official Gazettes and Their Contents (1985) and Government Gazettes Online are useful resources for finding these gazettes. The Library of Congress’s GLIN database indexes laws and regulations from the gazettes of selected countries; you can get summaries and citation information and the full text of documents for some countries.

United Nations Legislative Series is a collection of national laws concerning various areas of international law, but it is not complete for every country.

A Selective List of Guides to Foreign Legal Research provides links to research guides for many countries and regions around the world. These guides provide advice on researching the laws of these countries.

To find gazettes, session laws and statutory compilations of individual states, search library catalogs under the subject headings gazettes--[country]; session laws--[country]; [country]--law.