United States. Postmaster General. (1924). Ascertainment of cost of handling and transporting several classes of mail matter and conducting special services: Instruction letter P-R-T; parcel post. U.S. GPO.
Chicago Style (17th ed.) CitationUnited States. Postmaster General. Ascertainment of Cost of Handling and Transporting Several Classes of Mail Matter and Conducting Special Services: Instruction Letter P-R-T; Parcel Post. Washington: U.S. GPO, 1924.
MLA (9th ed.) CitationUnited States. Postmaster General. Ascertainment of Cost of Handling and Transporting Several Classes of Mail Matter and Conducting Special Services: Instruction Letter P-R-T; Parcel Post. U.S. GPO, 1924.
Warning: These citations may not always be 100% accurate.