APA (7th ed.) Citation

United States. Postmaster General. (1930). Delivery of mail from U.S. to foreign countries and certain U.S. possessions on or about Christmas. U.S. GPO.

Chicago Style (17th ed.) Citation

United States. Postmaster General. Delivery of Mail from U.S. to Foreign Countries and Certain U.S. Possessions on or About Christmas. Washington: U.S. GPO, 1930.

MLA (9th ed.) Citation

United States. Postmaster General. Delivery of Mail from U.S. to Foreign Countries and Certain U.S. Possessions on or About Christmas. U.S. GPO, 1930.