|
USA | |
| Eckel, Edwin Butt , Cobban, Robert R., Mosburg, Shirley K., Foord, Eugene E. (1997) Minerals of Colorado. Fulcrum Publishing. |
- Grayback Mining District (Russell Mining District)
| (2005) Mineral Resources Data System (MRDS), US Geological Survey. |
| (2005) Mineral Resources Data System (MRDS), US Geological Survey. |
| (2005) Mineral Resources Data System (MRDS), US Geological Survey. |
| (2005) Mineral Resources Data System (MRDS), US Geological Survey. |