United States. Postmaster General. (1927). Important: Statistics of foreign mail transactions. U.S. GPO.
Chicago Style (17th ed.) CitationUnited States. Postmaster General. Important: Statistics of Foreign Mail Transactions. Washington: U.S. GPO, 1927.
MLA (9th ed.) CitationUnited States. Postmaster General. Important: Statistics of Foreign Mail Transactions. U.S. GPO, 1927.
Warning: These citations may not always be 100% accurate.