United States. Post Office Department. (1927). Plants and plant products for propagation not to be accepted for mailing in violation of postal regulations. GPO.
Chicago Style (17th ed.) CitationUnited States. Post Office Department. Plants and Plant Products for Propagation Not to Be Accepted for Mailing in Violation of Postal Regulations. [Washington]: GPO, 1927.
MLA (9th ed.) CitationUnited States. Post Office Department. Plants and Plant Products for Propagation Not to Be Accepted for Mailing in Violation of Postal Regulations. GPO, 1927.
Warning: These citations may not always be 100% accurate.