APA (7th ed.) Citation

United States. Postmaster General. (1930). Undeliverable 2nd, 3rd, and 4th class matter bearing pledge to pay forwarding or return postage. U.S. GPO.

Chicago Style (17th ed.) Citation

United States. Postmaster General. Undeliverable 2nd, 3rd, and 4th Class Matter Bearing Pledge to Pay Forwarding or Return Postage. Washington: U.S. GPO, 1930.

MLA (9th ed.) Citation

United States. Postmaster General. Undeliverable 2nd, 3rd, and 4th Class Matter Bearing Pledge to Pay Forwarding or Return Postage. U.S. GPO, 1930.