APA (7th ed.) Citation

United States. Post Office Department. (1037). Postal bulletin, July 23, 1937. [s.n.].

Chicago Style (17th ed.) Citation

United States. Post Office Department. Postal Bulletin, July 23, 1937. [Washington]: [s.n.], 1037.

MLA (9th ed.) Citation

United States. Post Office Department. Postal Bulletin, July 23, 1937. [s.n.], 1037.

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