Não informado. (1926). Rocks and Minerals. Heldref Publications.
Chicagoスタイル(17版)引用形式Não informado. Rocks and Minerals. Washington: Heldref Publications, 1926.
MLA(8版)引用形式Não informado. Rocks and Minerals. Heldref Publications, 1926.
警告: この引用は必ずしも正確ではありません.