APA

U.S. Department of the Interior. Bureau of Mines information circular nr 8640, . (1974). Ash utilization. Washington DC: U.S. Department of the Interior. Bureau of Mines information circular nr 8640.

Chicago

U.S. Department of the Interior. Bureau of Mines information circular nr 8640, . 1974. Ash utilization. Washington DC: U.S. Department of the Interior. Bureau of Mines information circular nr 8640.

Harvard

U.S. Department of the Interior. Bureau of Mines information circular nr 8640, . (1974). Ash utilization. Washington DC: U.S. Department of the Interior. Bureau of Mines information circular nr 8640.

MLA

U.S. Department of the Interior. Bureau of Mines information circular nr 8640, . Ash utilization. Washington DC: U.S. Department of the Interior. Bureau of Mines information circular nr 8640. 1974.