Library of Congress. Environment and Natural Resources Policy Division & United States. Congress. Senate. Committee on Governmental Affairs. Permanent Subcommittee on Investigations. (1978). The coal industry: Problems and prospects : a background study. U.S. Govt. Print. Off. : for sale by the Supt. of Docs., U.S. Govt. Print. Off..
Cita Chicago (17th ed.)Library of Congress. Environment and Natural Resources Policy Division i United States. Congress. Senate. Committee on Governmental Affairs. Permanent Subcommittee on Investigations. The Coal Industry: Problems and Prospects : A Background Study. Washington: U.S. Govt. Print. Off. : for sale by the Supt. of Docs., U.S. Govt. Print. Off., 1978.
Cita MLA (8th ed.)Library of Congress. Environment and Natural Resources Policy Division i United States. Congress. Senate. Committee on Governmental Affairs. Permanent Subcommittee on Investigations. The Coal Industry: Problems and Prospects : A Background Study. U.S. Govt. Print. Off. : for sale by the Supt. of Docs., U.S. Govt. Print. Off., 1978.