United States. Postmaster General. (1928). Changes in postal rates effective July 1, 1928. U.S. GPO.
Chicago Style (17th ed.) CitationUnited States. Postmaster General. Changes in Postal Rates Effective July 1, 1928. Washington: U.S. GPO, 1928.
MLA (9th ed.) CitationUnited States. Postmaster General. Changes in Postal Rates Effective July 1, 1928. U.S. GPO, 1928.
Warning: These citations may not always be 100% accurate.