APA (7th ed.) Citation

United States. Postmaster General. (1820). Post-Office laws, instructions and forms, published for regulation of Post-Office. [publisher not identified].

Chicago Style (17th ed.) Citation

United States. Postmaster General. Post-Office Laws, Instructions and Forms, Published for Regulation of Post-Office. [Washington]: [publisher not identified], 1820.

MLA (9th ed.) Citation

United States. Postmaster General. Post-Office Laws, Instructions and Forms, Published for Regulation of Post-Office. [publisher not identified], 1820.