United States. Department of Commerce. (1920). Approved explosion-proof coal-cutting equipment. GPO.
Chicago Style (17th ed.) CitationUnited States. Department of Commerce. Approved Explosion-proof Coal-cutting Equipment. [Washington]: GPO, 1920.
MLA (9th ed.) CitationUnited States. Department of Commerce. Approved Explosion-proof Coal-cutting Equipment. GPO, 1920.
Warning: These citations may not always be 100% accurate.