Approved dust respirators for coal mines

Author:	Schutz, Robert H.
Year:	1971
Document Type:	USBI
Issuing Agency:	Bureau of Mines,
SUDOC:	I 28.27:8509
Series:	Information circular / United States. Bureau of Mines ;
Report Number:	8509
Subjects:	Mine dusts
	Respirators
Link:	https://hdl.handle.net/2027/mdp.39015078514877