Search U.S. government technical reports digitized or harvested by TRAIL.
State laws relating to coal-mine timbering
What the coal miners can do to prevent injury from falls of roof
A study of falls of roof and coal in mines in the number 8 field of eastern Ohio
A study of falls of roof and coal in mines of Harrison County, West Virginia
How to prevent death and injury from falls of roof in coal mines
Timber withdrawing and devices used for this purpose in some coal mines