APA

United States, . (1978). Inaccurate estimates of western coal reserves should be corrected. [Washington, D.C: .

Chicago

United States, . 1978. Inaccurate estimates of western coal reserves should be corrected. [Washington, D.C: .

Harvard

United States, . (1978). Inaccurate estimates of western coal reserves should be corrected. [Washington, D.C: .

MLA

United States, . Inaccurate estimates of western coal reserves should be corrected. [Washington, D.C: . 1978.