-
حسب Zapffe, Carl, 1880-1950
منشور في 1949 -
حسب Whittier, William Harrison
منشور في 1917 -
Report on the mining industries of the United States (exclusive of the precious metals)with special investigation into the iron resources of the republic and into the Cretaceous coals of the NorthwestBookحسب Pumpelly, Raphael, 1837-1923
منشور في 1886