Não informado. (1967). Minerals Yearbook. U.S. Department of the Interior, Bureau of Mines.
Style de citation Chicago (17e éd.)Não informado. Minerals Yearbook. Washington: U.S. Department of the Interior, Bureau of Mines, 1967.
Style de citation MLA (8e éd.)Não informado. Minerals Yearbook. U.S. Department of the Interior, Bureau of Mines, 1967.
Attention : ces citations peuvent ne pas être correctes à 100%.