United States. Postmaster General. (1924). Letters, or articles sent as letters, destined for delivery in foreign countries will be accepted for transmission by Air Mail Service between New York and San Francisco. [publisher not identified].
Chicago Style (17th ed.) CitationUnited States. Postmaster General. Letters, or Articles Sent as Letters, Destined for Delivery in Foreign Countries Will Be Accepted for Transmission by Air Mail Service Between New York and San Francisco. Washington: [publisher not identified], 1924.
MLA (9th ed.) CitationUnited States. Postmaster General. Letters, or Articles Sent as Letters, Destined for Delivery in Foreign Countries Will Be Accepted for Transmission by Air Mail Service Between New York and San Francisco. [publisher not identified], 1924.