Mechanical mining in some bituminous-coal mines.

Author:	Turnbull, Louis A.
Additional Authors:	Toenges, Albert L.
Year:	1949
Document Type:	USBI
Issuing Agency:	U.S. Dept. of the Interior, Bureau of Mines,
SUDOC:	I 28.27:7527
Series:	Information circular / Bureau of Mines ;
Report Number:	7527
Subjects:	Bituminous coal
	Coal mines and mining--Equipment and supplies
Link:	https://hdl.handle.net/2027/mdp.39015078463687