United States. Postmaster General. (1929). Resubmitted requisitions for special-request envelopes not to be marked "duplicate". U.S. GPO.
Chicago Style (17th ed.) CitationUnited States. Postmaster General. Resubmitted Requisitions for Special-request Envelopes Not to Be Marked "Duplicate". Washington: U.S. GPO, 1929.
MLA (9th ed.) CitationUnited States. Postmaster General. Resubmitted Requisitions for Special-request Envelopes Not to Be Marked "Duplicate". U.S. GPO, 1929.
Warning: These citations may not always be 100% accurate.