Alstine, Ralph E. van 1914- Geology and mineral deposits of the Poncha springs SE quadrangle, chaffee county, Colorado / by Ralph E. van Alstine. -- Washington : United States Government Printing Office, 1974 - 19 p. + map. -- (Geological Survey Professional Paper ; 829). Subjects--Topical Terms: ColoradoDepósitos de minerales Universal Decimal Class. No.: 553(788)