APA (7th ed.) Citation

United States. Army. Air Corps. (1919). Valve timing for airplane engines. U.S. GPO.

Chicago Style (17th ed.) Citation

United States. Army. Air Corps. Valve Timing for Airplane Engines. Washington: U.S. GPO, 1919.

MLA (9th ed.) Citation

United States. Army. Air Corps. Valve Timing for Airplane Engines. U.S. GPO, 1919.

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