Somers, G.B., and Shoemaker, A.H., 1924, Geology of the El Tiro mine, Silver Bell, Arizona: Tucson, University of Arizona, M.S. thesis, 40 p.
Somers, G.B., and Shoemaker, A.H.
Tucson, University of Arizona, M.S. thesis, 40 p.
Areal, Structure, Stratigraphy, Porphyry Copper, Mineralization,