Studies of roof movement in coal mines.

Author:	Maize, Earl R.
Additional Authors:	Greenwald, H. P.
Year:	1939
Document Type:	BMRA
Issuing Agency:	U.S. Dept. of the Interior, Bureau of Mines,
SUDOC:	I 28.23:3452
Series:	Report of investigations / United States Department of the Interior, Bureau of Mines ;
Report Number:	3452
Subjects:	Coal mines and mining
	Mine roof control
Link:	https://hdl.handle.net/2027/mdp.39015078492397