Some observations as to safety hazards in 47 northern Colorado subbituminous coal mines

Author:	Denny, E. H.
Year:	1935
Document Type:	USBI
Issuing Agency:	U.S. Dept. of the Interior, Bureau of Mines,
SUDOC:	I 28.27:6862
Series:	Information circular / United States Department of the Interior, Bureau of Mines ;
Report Number:	6862
Subjects:	Coal mines and mining--Colorado
	Mine accidents--Colorado
	Mine safety--Colorado
Link:	https://hdl.handle.net/2027/mdp.39015077568684