Search U.S. government technical reports digitized or harvested by TRAIL.
A study of falls of roof and coal in mines in the number 8 field of eastern Ohio
Roof support in coal mines in the Irwin, Greensburg and Latrobe Basins, Westmoreland County, Pa.
A study of falls of roof and coal in mines of Harrison County, West Virginia
Falls of roof and coal in the Book Cliffs and Wasatch Plateau Coal Fields in Utah
A study of falls of roof and coal in mines of Lincoln County, Wyoming
A study of mine roof of the Pittsburgh coal bed in the Pittsburgh mining district
A study of falls of roof and coal in Northern Colorado
A study of falls of roof and coal, Rock Springs Coal District, Sweetwater County, Wyo.
Timber withdrawing and devices used for this purpose in some coal mines