United States. Postmaster General. (1928). First-class matter not to be accepted for insurance or transmission as C.O.D. mail. U.S. GPO.
Chicago Style (17th ed.) CitationUnited States. Postmaster General. First-class Matter Not to Be Accepted for Insurance or Transmission as C.O.D. Mail. Washington: U.S. GPO, 1928.
MLA (9th ed.) CitationUnited States. Postmaster General. First-class Matter Not to Be Accepted for Insurance or Transmission as C.O.D. Mail. U.S. GPO, 1928.
Warning: These citations may not always be 100% accurate.