Active list of permissible explosives and blasting devices approved prior to June 30. 1931.

Year:	1931
Document Type:	BMRA
Issuing Agency:	United States Bureau of Mines,
SUDOC:	C 22.12:3134
Series:	Report of investigations / United States Department of the Interior, Bureau of Mines ;
Report Number:	3134
Subjects:	Explosives
	Coal mines and mining--Safety measures
Link:	https://hdl.handle.net/2027/mdp.39015077567660