Experimental longwall mining in a Pennsylvania anthracite mine (In two parts).

Author:	Brennan, Robert J.
Additional Authors:	Buch, John W., Navrocky, Edward R.
Year:	1964
Document Type:	BMRA
Issuing Agency:	U.S. Dept. of the Interior, Bureau of Mines,
SUDOC:	I 28.23:6378
Series:	Report of investigations / Bureau of Mines ;
Report Number:	6378
Subjects:	Mining engineering
	Roofs
Link:	https://hdl.handle.net/2027/mdp.39015077556788