APA (7th ed.) Citation

United States. War Department. (1921). Air Service: General provisions. GPO.

Chicago Style (17th ed.) Citation

United States. War Department. Air Service: General Provisions. [Washington]: GPO, 1921.

MLA (9th ed.) Citation

United States. War Department. Air Service: General Provisions. GPO, 1921.

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