APA (7th ed.) Citation

United States. Postmaster General. (1932). New 8-cent air mail stamps and stamped envelopes. U.S. GPO.

Chicago Style (17th ed.) Citation

United States. Postmaster General. New 8-cent Air Mail Stamps and Stamped Envelopes. Washington: U.S. GPO, 1932.

MLA (9th ed.) Citation

United States. Postmaster General. New 8-cent Air Mail Stamps and Stamped Envelopes. U.S. GPO, 1932.

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