|
USA | |
| USGS PP 610 (Koschman,1968) |
| Spurr, J. E., Garrey, G. H., and Ball, S. H. (1908), Economic Geology of the Georgetown Quadrangle (Together with the Empire District), Colorado. With General Geology Professional Paper 63: 253. |
| Eckel, Edwin Butt , Cobban, Robert R., Mosburg, Shirley K., Foord, Eugene E. (1997) Minerals of Colorado. Fulcrum Publishing. Lovering, T.S., Goddard, E.N. (1950) Geology and ore deposits of the Front Range, Colorado. Professional Paper 223. US Geological Survey doi:10.3133/pp223 |
| Eckel, Edwin Butt , Cobban, Robert R., Mosburg, Shirley K., Foord, Eugene E. (1997) Minerals of Colorado. Fulcrum Publishing. |
| USGS PP 223(Lovering,1950) |
| Eckel, Edwin Butt , Cobban, Robert R., Mosburg, Shirley K., Foord, Eugene E. (1997) Minerals of Colorado. Fulcrum Publishing. |