A study of mine roof of the coking district of Western Pennsylvania

Author:	Paul, J. W.
Additional Authors:	Plein, Leopold Nicholas,
Year:	1935
Document Type:	USBM
Issuing Agency:	U.S. Dept. of the Interior, Bureau of Mines,
SUDOC:	I 28.7:563
Series:	Technical paper / United States Department of the Interior, Bureau of Mines ;
Report Number:	563
Subjects:	Coal mines and mining--Pennsylvania
	Industrial accidents--Pennsylvania
	Coke--Pennsylvania
	Mine safety--Pennsylvania
Link:	https://hdl.handle.net/2027/mdp.39015077565433