United States. Bureau of Mines. (1937). Design of small wooden head frames [for mine shafts]. [s.n.].
Chicago Style (17th ed.) CitationUnited States. Bureau of Mines. Design of Small Wooden Head Frames [for Mine Shafts]. [Washington]: [s.n.], 1937.
MLA (9th ed.) CitationUnited States. Bureau of Mines. Design of Small Wooden Head Frames [for Mine Shafts]. [s.n.], 1937.
Warning: These citations may not always be 100% accurate.