APA (7th ed.) Citation

United States. Army. Air Corps. (1920). Observation balloons serving infantry. U.S. GPO.

Chicago Style (17th ed.) Citation

United States. Army. Air Corps. Observation Balloons Serving Infantry. Washington: U.S. GPO, 1920.

MLA (9th ed.) Citation

United States. Army. Air Corps. Observation Balloons Serving Infantry. U.S. GPO, 1920.

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