Frictional ignition of gas by mining machines

Author:	Hartmann, Irving.
Year:	1955
Document Type:	USBI
Issuing Agency:	U.S. Dept. of the Interior, Bureau of Mines,
SUDOC:	I 28.27:7727
Series:	Information circular / United States. Bureau of Mines ;
Report Number:	7727
Subjects:	Mine explosions--United States
	Mine gases
	Mine explosions--Germany
	Mine explosions--Great Britain
Link:	https://hdl.handle.net/2027/mdp.39015078459362