Bureau of Mines approval system for respiratory protective devices

Author:	Pearce, S. J.
Year:	1951
Document Type:	USBI
Issuing Agency:	U.S. Dept. of the Interior, Bureau of Mines,
SUDOC:	I 28.27:7600
Series:	Information circular / United States. Bureau of Mines ;
Report Number:	7600
Subjects:	Respirators (Medical equipment)
	Breathing apparatus
Link:	https://hdl.handle.net/2027/mdp.39015078455626