U.S. Bureau of Mines, 1944, Suggested mining methods at Christmas Mine, Gila County, Ariz.: U.S. Bureau of Mines War Minerals Report 291, 12 p.
U.S. Bureau of Mines
U.S. Bureau of Mines War Minerals Report 291, 12 p.
Porphyry Copper, Skarn, Mining Engineering, Mineralization, Subsurface,