APA (7th ed.) Citation

United States. Army. Air Corps. (1918). Laminated spars. [publisher not identified].

Chicago Style (17th ed.) Citation

United States. Army. Air Corps. Laminated Spars. [Place of publication not identified]: [publisher not identified], 1918.

MLA (9th ed.) Citation

United States. Army. Air Corps. Laminated Spars. [publisher not identified], 1918.