APA (7th ed.) Citation

United States. Bureau of Mines. (1937). Electric signaling system, Ross shaft, Homestake Mining Co. [s.n.].

Chicago Style (17th ed.) Citation

United States. Bureau of Mines. Electric Signaling System, Ross Shaft, Homestake Mining Co. [Washington]: [s.n.], 1937.

MLA (9th ed.) Citation

United States. Bureau of Mines. Electric Signaling System, Ross Shaft, Homestake Mining Co. [s.n.], 1937.