Modified longwall mining with German coal planers :summary of operations at five coal mines

Author:	Haley, Wilbur A.
Additional Authors:	Dowd, James J.
Year:	1957
Document Type:	BMRA
Issuing Agency:	U.S. Dept. of the Interior, Bureau of Mines,
SUDOC:	I 28.23:5355
Series:	Report of investigations / United States Department of the Interior, Bureau of Mines ;
Report Number:	5355
Subjects:	Longwall mining--Equipment and supplies
	Coal-mining machinery
Link:	https://hdl.handle.net/2027/mdp.39015078468942