The Grand Gulch mining region, Mohave County, Arizona, in Copper, in Contributions to economic geology, 1913, Part I - Metals and nonmetals except fuels
Hill, J.M., 1914, The Grand Gulch mining region, Mohave County, Arizona, in Copper, in Contributions to economic geology, 1913, Part I - Metals and nonmetals except fuels: U.S. Geological Survey Bulletin 580, p. 39-58.