APA (7th ed.) Citation

(1939). Postal bulletin, Dec. 22, 1939. [s.n.].

Chicago Style (17th ed.) Citation

Postal Bulletin, Dec. 22, 1939. [Washington]: [s.n.], 1939.

MLA (9th ed.) Citation

Postal Bulletin, Dec. 22, 1939. [s.n.], 1939.

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