(1968). United States government correspondence manual. U.S. Government Printing Office.
Chicago-referens (17:e uppl.)United States Government Correspondence Manual. Washington: U.S. Government Printing Office, 1968.
MLA-referens (9:e uppl.)United States Government Correspondence Manual. U.S. Government Printing Office, 1968.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.