APA (7th ed.) Citation

United States. Postmaster General & Washington, G. (1932). Postmark of Mount Vernon (Va.) post office on Feb. 22. U.S. GPO.

Chicago Style (17th ed.) Citation

United States. Postmaster General and George Washington. Postmark of Mount Vernon (Va.) Post Office on Feb. 22. Washington: U.S. GPO, 1932.

MLA (9th ed.) Citation

United States. Postmaster General and George Washington. Postmark of Mount Vernon (Va.) Post Office on Feb. 22. U.S. GPO, 1932.

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