Falls of roof in bituminous coal mines :influence of the seasons and rate of production

Author:	Paul, J. W.
Year:	1929
Document Type:	USBM
Issuing Agency:	U.S. Dept. of Commerce, Bureau of Mines :
SUDOC:	C 22.5:410
Series:	Technical paper / United States Department of Commerce, Bureau of Mines ;
Report Number:	410
Subjects:	Bituminous coal
	Coal mine accidents
Link:	https://hdl.handle.net/2027/mdp.39015078543223