APA (7th ed.) Citation

United States. Army. Air Corps. (1921). Test of airplane engine heater. U.S. GPO.

Chicago Style (17th ed.) Citation

United States. Army. Air Corps. Test of Airplane Engine Heater. Washington: U.S. GPO, 1921.

MLA (9th ed.) Citation

United States. Army. Air Corps. Test of Airplane Engine Heater. U.S. GPO, 1921.

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