The U. S. Congressional Serial Set, commonly referred to as the Serial Set, contains House and Senate Documents, House and Senate Reports, Senate Executive Documents and Senate Executive Reports bound by the session of Congress. Documents cover a wide variety of topics and history. Publication of the Serial Set began with the 15th Congress, 1st Session (1817). The Law Library of Congress and the Government Publishing Office (GPO) are collaborating to digitize Serial Set documents published between the 15th (1817) and 103rd (1994) Congresses (See Serial Set timeline (e)). These are important historical resources that include not only legal and committee reports related to bills and foreign affairs, but also geographical information.