Geology of the Paleozoic rocks, Navajo and Hopi Indian Reservations, Arizona, New Mexico, and Utah - Irwin, James H. (James Haskell), 1923-; Stevens, Peter R. (Peter Ryan), 1924-; Cooley, M. E. (Maurice E.) (Hydrogeology of the Navajo and Hopi Indian Reservations, Arizona, New Mexico, and Utah., 1971)