APA (7th ed.) Citation

United States. Army. Air Corps. (1923). Harrisburg to Pittsburgh, Pa. [publisher not identified].

Chicago Style (17th ed.) Citation

United States. Army. Air Corps. Harrisburg to Pittsburgh, Pa. Washington: [publisher not identified], 1923.

MLA (9th ed.) Citation

United States. Army. Air Corps. Harrisburg to Pittsburgh, Pa. [publisher not identified], 1923.

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