Search U.S. government technical reports digitized or harvested by TRAIL.
Kettlebottoms :their relation to mine roof and support
Coal mine air tempering :effectiveness, design, and roof support
The character of five selected LANDSAT lineaments in southwestern Pennsylvania
Hillseam geology and roof instability near outcrop in eastern Kentucky drift mines
Roof control of stress-relief jointing near outcrops in central Appalachian drift coal mines