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Pritzker Legal Research Center

International Legal Research Guide

An overview of international law and where to begin research


Treaties can be found in various electronic databases or in print. The full-text of a treaty may be published in several different publications or databases. If you do not have a known citation, use a treaty index or a secondary source to identify the citation(s) for the treaty.

Treaty Indexes

Treaty indexes are additional finding tools beyond books and articles that can assist you with identifying citations to relevant treaties. An index will provide the citation only, not the full-text copy of the treaty.

Indexes for Finding Treaties Where the United States Is a Party
Indexes for Finding Treaties Where the United States Is Not a Party

Official U.S. Treaty Sources

United States Treaties and Other International Agreements (U.S.T.) 

Treaties and agreements that entered into force between 1950–1984 were published in these bound volumes. The GPO no longer publishes the UST in print. 

Statutes at Large (Stat.)

Prior to 1950, treaties and international agreements were officially printed in the U.S. Statutes at Large. 

Treaties and Other International Acts Series (T.I.A.S.)

This is the slip form for a treaty or international agreement. The GPO no longer publishes the TIAS in print, but continues to publish it electronically. This is often the best official U.S. source for treaties because the last volume of the U.S.T. was published in 1984.

Treaty Series (T.S.)

In 1946, the Treaty Series merged with the Executive Agreement Series to form T.I.A.S. 

Executive Agreement Series (E.A.S.)

In 1946, the Executive Agreement Series merged with the Treaty Series to form T.I.A.S. 

Senate Treaty Documents and Senate Executive Documents (S. Treaty Doc. No. / S. Exec. Doc. No.)

The Senate Treaty Documents and Senate Executive Documents contain the text of treaties submitted to the U.S. Senate for ratification by the President. Beginning with the 97th Congress in 1981, Executive Documents became known as Treaty Documents. 

Intergovernmental Treaty Sources

United Nations Treaty Series

The UNTS includes all treaties and international agreements registered or filed and recorded by the Secretariat of the UN since 1945. 

League of Nations Treaty Series

The LNTS contains all treaties registered with the League of Nations (the predecessor to the United Nations). 

Organization of American States (OAS) Treaty Series

The OAS Treaty Series began in 1957 and continued the consecutive numbering of the Pan American Union Treaty Series. 

European Treaty Series & Council of Europe Treaty Series

The European Treaty Series contains conventions and agreements opened for signature between 1949 and 2003. The Council of Europe Treaty Series continued the European Treaty Series starting in 2004. 

Unofficial Treaty Sources

U.S. Treaties on LEXIS

This source contains all un-ratified and ratified U.S. treaties and international agreements from 1776-present. 

International Legal Materials (I.L.M.)

This is a secondary source that reproduces selected primary international legal documents. 

Hein's United States and Other Agreements (KAV Agreements)

This set contains treaties and agreements not yet published in U.S.T. or T.I.A.S., each of which gets assigned a KAV number. 


This collection contains treaties and international agreements that the United States entered into from 1776 to 1949. 

Country Series

In addition to checking sources for intergovernmental treaties, another helpful strategy to find treaties where the United States is not a party is to see whether one of the countries that is a party to the treaty has a country series (e.g., Australian Treaty Series).