Multiple-shift mechanical mining in some bituminous coal mines.

Author:	Toenges, Albert L.
Additional Authors:	Anderson, Robert L.
Year:	1938
Document Type:	USBI
Issuing Agency:	U.S. Dept. of the Interior, Bureau of Mines,
SUDOC:	I 28.27:7014
Series:	Information circular / Bureau of Mines ;
Report Number:	7014
Subjects:	Bituminous coal industry--United States
	Coal-mining machinery
Link:	https://hdl.handle.net/2027/mdp.39015077575838