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| - 1-211, Gale, H.S.; Richardson, G.B.; Taff, J.A.; Lee, W.T., 1907, Contributions to economic geology, 1906, Part II, Coal, lignite, and peat--coal fields of Colorado and Utah: Bulletin 316-E, p. 264-375, Gale, H.S.; Smith, George Otis; Kay, George Frederick, 1907, Contributions to economic geology 1906 : Part I - metals and nonmetals except fuels -- Nickel, Uranium, etc.; Lead and Zinc: Bulletin 31
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