Search U.S. government technical reports digitized or harvested by TRAIL.
Modified longwall mining with a German coal planer (plow) in the Pocohontas No. 4 coal bed, Helen, W. Va.
Mining with a Dosco continuous miner on a longwall face
Modified longwall mining with German coal planers :summary of operations at five coal mines
The use of augers in surface mining of bituminous coal