APA (7th ed.) Citation

United States. Postmaster General. (1930). Undeliverable mail matter of 1st class bearing sender's return request must be promptly returned. U.S. GPO.

Chicago Style (17th ed.) Citation

United States. Postmaster General. Undeliverable Mail Matter of 1st Class Bearing Sender's Return Request Must Be Promptly Returned. Washington: U.S. GPO, 1930.

MLA (9th ed.) Citation

United States. Postmaster General. Undeliverable Mail Matter of 1st Class Bearing Sender's Return Request Must Be Promptly Returned. U.S. GPO, 1930.