These research guides and other books that address working with treaties are available via the SLU Law Library catalog. These can be helpful for in-depth exploration, including researching the status of treaties, locating more obscure treaties (such as bilateral agreements to which the U.S. is not a party) and locating texts not available in English.
Also called "negotiating history" or "drafting history," a treaty's travaux préparatoires (or preparatory works) can be consulted to assist in treaty interpretation.