Coal mine roof instability :categories and causes

Author:	Moebs, Noel N.
Additional Authors:	Stateham, Raymond M.
Year:	1986
Document Type:	USBI
Issuing Agency:	U.S. Dept. of the Interior, Bureau of Mines,
SUDOC:	I 28.27:9076
Series:	Information circular / Bureau of Mines ;
Report Number:	9076
Subjects:	Coal mines and mining--Safety measures
	Mine roof control
	Coal--Geology
Link:	https://hdl.handle.net/2027/mdp.39015078459057