United States. Post Office Department. (1921). Postal laws and regulations applicable to post office clerks and city carriers. GPO.
Chicago Style (17th ed.) CitationUnited States. Post Office Department. Postal Laws and Regulations Applicable to Post Office Clerks and City Carriers. [Washington]: GPO, 1921.
MLA (9th ed.) CitationUnited States. Post Office Department. Postal Laws and Regulations Applicable to Post Office Clerks and City Carriers. GPO, 1921.
Warning: These citations may not always be 100% accurate.