Chalcopyrite from Breckenridge Mining District, Summit County, Colorado, USA
USA | |
| USGS Professional Paper 75 |
| USGS Professional Paper 75 |
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 USGS Proffesional Paper 75 | |
(2005) Mineral Resources Data System (MRDS), US Geological Survey. |