There are many international tribunals in existence, including the International Court of Justice, a body of the United Nations. Cases are helpful sources, because they are concrete and tangible, easily consulted (as opposed to the indefiniteness of customary law), and familiar to most legal researchers. Researchers must note, however, that Article 38 of the ICJ Statute refers to judicial decisions as "subsidiary means" for determining rules of law, making them secondary to treaties and international agreements, customary law, and general principles of law in the international law hierarchy.
There are three types of "international" judicial decisions:
In most cases, the best place to find decisions from international tribunals is on each tribunal's website. In most cases, researchers are able to browse or keyword search for cases.
International Court of Justice
Decisions are printed in a reporter series called the Reports of Judgments, Advisory Opinions & Orders. Because the reporter is abbreviated as I.C.J. in The Bluebook, it's often referenced as ICJ Reports. The reporter is available in Hein Online's United Nations Law Collection (find Hein under Quick Links on the library's homepage) as well as on the ICJ website.
European Court of Human Rights:
The ECHR's decisions are published in the Reports of Judgments and Decisions. Volumes 2007-2013 are available on the ECHR website, along with e-Reports. There is a also a search database from the Case Law page that allows researchers to search for "Recent judgments" and "Recent decisions".
Inter-American Court of Human Rights
The IACHR keeps an archive of past case decisions going back to 1970. Researchers can browse by year to find the case they are looking for.
African Court on Human and Peoples' Rights
Researchers can search for pending and completed cases on the Court's website.
International Criminal Court
Researchers can browse for cases by location and party name. Once they select a specific case, they can select court records on the right hand side to find a list of documents related to the case. They can filter the results by chamber (appellate or trial level) and by who filed the document (defence, prosecutor, state representatives, etc.).
International Criminal Tribunal for the former Yugoslavia
Researchers can browse for cases by accused name or search by case number, which will lead them to a case information sheet and a link for important documents (indictments, transcripts, decisions, orders, etc.). Researchers can also search in the MICT/ICTR/ICTY Case Law Database, which contains extracts of judgments and decisions of certain international criminal tribunals. Researchers can filter by court and search by issues to find documents on their specific issues.
International Criminal Tribunal for Rwanda
Researchers can search by the accused's name on the ICTR's website, or browse by case number. Researchers can also browse by topic or by accused's name, and filter by language, date, etc., using the ICTR Basic Documents and Case Law Advanced Browse feature. Researchers can also do a keyword search on that site. Researchers can also search in the MICT/ICTR/ICTY Case Law Database, which contains extracts of judgments and decisions of certain international criminal tribunals. Researchers can filter by court and search by issues to find documents on their specific issues.
Extraordinary Chambers in the Courts of Cambodia
Researchers can do an advanced search by case, date, indicted party, by an important article or rule number, or by important legal terms. Researchers can also browse by document date, chamber, and who filed.
Special Court for Sierra Leone
Researchers can search for court documents by case, and can narrow to the types of materials they want. Researchers can also search for videos and transcripts, or run an advanced keyword search and filter by case and/or type of document desired.
Special Tribunal for Lebanon
European Union's Court of Justice
WTO's Dispute Settlement Body