Search U.S. government technical reports digitized or harvested by TRAIL.
Diamond-drilling blast holes, eastern Magnetite Mine A
Diamond drilling blast holes, Balmat Mine, St. Lawrence County, N.Y.
Shaft sinking by diamond drilling, Bellefonte mine, National Gypsum Co., Centre County, Pa.
Diamond-drilling blast holes, Bellefonte Mine, National Gypsum Co., Centre County, Pa.