APA (7th ed.) Citation

United States. Postmaster General. (1922). Mail door-slot or receptacle required. [publisher not identified].

Chicago Style (17th ed.) Citation

United States. Postmaster General. Mail Door-slot or Receptacle Required. Washington: [publisher not identified], 1922.

MLA (9th ed.) Citation

United States. Postmaster General. Mail Door-slot or Receptacle Required. [publisher not identified], 1922.

Warning: These citations may not always be 100% accurate.