Roepke, Wallace W.
Bit ignition potential with worn carbide tips (BM-TPR 121) Roepke, Wallace W. - Washington Bureau of mines 1983
TECNOLOGIA MINERA
622.06
Bit ignition potential with worn carbide tips (BM-TPR 121) Roepke, Wallace W. - Washington Bureau of mines 1983
TECNOLOGIA MINERA
622.06