Economic benefits of systematic roof bolting in Ziegler No. 3 Mine, Bell & Zoller Coal & Mining Co., Williamson County, Ill.,

Author:	Kelly, L. W.
Year:	1952
Document Type:	USBI
Issuing Agency:	U.S. Dept. of the Interior, Bureau of Mines,
SUDOC:	I 28.27:7633
Series:	Information circular / United States. Bureau of Mines ;
Report Number:	7633
Subjects:	Coal mines and mining--Safety measures
	Mine roof bolting
	Mine accidents--Illinois
Link:	https://hdl.handle.net/2027/mdp.39015078455808