APA (7th ed.) Citation

United States. Postmaster General. (1932). Cost ascertainment: Instruction letter I; 3rd and 4th class post offices. U.S. GPO.

Chicago Style (17th ed.) Citation

United States. Postmaster General. Cost Ascertainment: Instruction Letter I; 3rd and 4th Class Post Offices. Washington: U.S. GPO, 1932.

MLA (9th ed.) Citation

United States. Postmaster General. Cost Ascertainment: Instruction Letter I; 3rd and 4th Class Post Offices. U.S. GPO, 1932.

Warning: These citations may not always be 100% accurate.