This article is from the Copyright Law FAQ, by Terry Carroll with numerous contributions by others.
Treaties are compiled in several treaty sources. If the U.S.
is a party, the treaty will generally be found in United States Treaties
and Other International Agreements (U.S.T.) or Treaties and Other
International Acts Series (T.I.A.S.). In some cases (especially with
older treaties signed before the State Department took on their
publication), they'll be in Statutes at Large; in some case (especially
with important newer treaties not yet published by the State Department),
they'll be in the private versions of the U.S. Code.
If the U.S. is not a party, the treaty won't be in the above sources. It
might be found the United Nations Treaty Series (U.N.T.S.) (or the League
of Nations Treaty Series (L.N.T.S.) for older treaties), the Pan-American
Treaty Series (Pan-Am. T.S.) or European Treaty Series (Europ. T.S.).
In addition, treaties may be found in many unofficial compilations, e.g.,
International Legal Materials (I.L.M.), Basic Documents of International
Economic Law (B.D.I.E.L.), Bevans, and Kavass (KAV).
This is only a small list of treaty sources. For more sources, see "The
Bluebook: A Uniform System of Citation, 15th Edition," in particular,
table T.4 (Treaty Sources).
Generally, treaties are cited in the standard way: volume number,
reporter, and page number (e.g., the Berne Convention is 1 B.D.I.E.L.
715). A few series (e.g., T.I.A.S. and Europ. T.S.) are cited by treaty
number within the series, with no volume number specified.
The document "Treaties In Force" lists all the treaties to which the U.S.
is a party, and it lists all the other nations that are also a party.
This is a good source to find out if a particular nation is a signatory
to a particular treaty.
One final note on treaties: In section 4.1, many citations to treaties
look like typographical errors: "Art. 6bis" and "Art. 11ter," for
example. Well, these aren't typos. "bis," "ter, and "quater" are
suffixes derived from the French words for "second," "third," and
"fourth," respectively These suffixes are used when a treaty has already
been written, and a revision will insert a new article between already
existing articles. This avoids the need to renumber the treaty articles,
and so provides a consistency between multiple revisions of the treaties.
For example, Article 6bis of the Berne Convention is an article that was
inserted between Article 6 and Article 7 when the convention text was
revised. (This is also the reason why some modems are advertised as
supporting the V.32 protocol, while others support V.32bis, in case
you've ever wondered.)