United States. Department of the Treasury. (1931). Customs regulations of U.S. prescribed for instruction and guidance of customs officers, edition of 1931. GPO.
Chicago Style (17th ed.) CitationUnited States. Department of the Treasury. Customs Regulations of U.S. Prescribed for Instruction and Guidance of Customs Officers, Edition of 1931. [Washington]: GPO, 1931.
MLA (9th ed.) CitationUnited States. Department of the Treasury. Customs Regulations of U.S. Prescribed for Instruction and Guidance of Customs Officers, Edition of 1931. GPO, 1931.
Warning: These citations may not always be 100% accurate.