APA (7th ed.) Citation

United States. Post Office Department. (1931). Statement of postal receipts at 50 selected offices for month of 1931. [publisher not identified].

Chicago Style (17th ed.) Citation

United States. Post Office Department. Statement of Postal Receipts at 50 Selected Offices for Month of 1931. [Washington]: [publisher not identified], 1931.

MLA (9th ed.) Citation

United States. Post Office Department. Statement of Postal Receipts at 50 Selected Offices for Month of 1931. [publisher not identified], 1931.

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