APA (7th ed.) Citation

United States. National Advisory Committee for Aeronautics. (1938). Tests of a contra℗--propeller for aircraft. [s.n.].

Chicago Style (17th ed.) Citation

United States. National Advisory Committee for Aeronautics. Tests of a Contra℗--propeller for Aircraft. [Washington]: [s.n.], 1938.

MLA (9th ed.) Citation

United States. National Advisory Committee for Aeronautics. Tests of a Contra℗--propeller for Aircraft. [s.n.], 1938.