APA (7th ed.) Citation

United States. National Advisory Committee for Aeronautics. (1939). Knocking in Otto℗--cycle engine. [s.n.].

Chicago Style (17th ed.) Citation

United States. National Advisory Committee for Aeronautics. Knocking in Otto℗--cycle Engine. [Washington]: [s.n.], 1939.

MLA (9th ed.) Citation

United States. National Advisory Committee for Aeronautics. Knocking in Otto℗--cycle Engine. [s.n.], 1939.

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