APA (7th ed.) Citation

United States. Bureau of Mines. (1940). Annual report of research and technologic work on coal, fiscal year 1939. [s.n.].

Chicago Style (17th ed.) Citation

United States. Bureau of Mines. Annual Report of Research and Technologic Work on Coal, Fiscal Year 1939. [Washington]: [s.n.], 1940.

MLA (9th ed.) Citation

United States. Bureau of Mines. Annual Report of Research and Technologic Work on Coal, Fiscal Year 1939. [s.n.], 1940.