Não informado. (1926). Rocks and Minerals. Heldref Publications.
Style de citation Chicago (17e éd.)Não informado. Rocks and Minerals. Washington: Heldref Publications, 1926.
Style de citation MLA (8e éd.)Não informado. Rocks and Minerals. Heldref Publications, 1926.
Attention : ces citations peuvent ne pas être correctes à 100%.