United States. Bureau of Mines. (1939). Marketing talc, pyrophyllite, and ground soapstone. [s.n.].
Chicago Style (17th ed.) CitationUnited States. Bureau of Mines. Marketing Talc, Pyrophyllite, and Ground Soapstone. [Washington]: [s.n.], 1939.
MLA (9th ed.) CitationUnited States. Bureau of Mines. Marketing Talc, Pyrophyllite, and Ground Soapstone. [s.n.], 1939.
Warning: These citations may not always be 100% accurate.