Some information for miners about coal-mine ventilation

Author:	Miller, A. U.
Year:	1940
Document Type:	USBI
Issuing Agency:	U.S. Dept. of the Interior, Bureau of Mines,
SUDOC:	I 28.27:7137
Series:	Information circular / Bureau of Mines ;
Report Number:	7137
Subjects:	Ventilation systems--Coal mines and mining
	Mine ventilation
Link:	https://hdl.handle.net/2027/mdp.39015078534289