U.S. Government publications are arranged by the Superintendent of Documents classification number, commonly referred to as the SuDoc number. Publications are grouped together by issuing agency, using letters of the alphabet. D is for the Defense Department, ED for the Education Department, GP for Government Publishing Office, J for Justice Department, JU for Judiciary, X,Y for Congress, and Y 4 for Congressional Committees.
For assistance with the prefixes for any U.S. Government agency and any other information that can help you find the materials you need, please contact the library's reference librarians.
Many U.S. Government publications are available online, and some are issued also in other formats. Consult your library's online catalog for availability of government publications.
Construction of the Superintendent of Documents classification number for the publication The World Factbook:
Executive Office of the President (issuing agency)
Central Intelligence Agency (subordinate bureau within the issuing agency)
Number designating the title
Year of publication or coverage