Studies of roof movement in coal mines.

Additional Authors:	Maize, E. R., Greenwald, H. P., Hartmann, Irving, Rice, G. S.
Year:	1937
Document Type:	BMRA
Issuing Agency:	U.S. Dept. of the Interior, Bureau of Mines,
SUDOC:	I 28.23:3355
Series:	Report of investigations / United States Department of the Interior, Bureau of Mines ;
Report Number:	3355
Subjects:	Coal mines and mining--Pennsylvania
	Mine roof control
Link:	https://hdl.handle.net/2027/mdp.39015078518712