APA (7th ed.) Citation

United States. Patent Office. (1931). Rules of practice in Patent Office, revised Feb. 1, 1931. GPO.

Chicago Style (17th ed.) Citation

United States. Patent Office. Rules of Practice in Patent Office, Revised Feb. 1, 1931. [Washington]: GPO, 1931.

MLA (9th ed.) Citation

United States. Patent Office. Rules of Practice in Patent Office, Revised Feb. 1, 1931. GPO, 1931.