Development of a transistor-type telephone system for mine rescue operations

Author:	Brown, Clyde L.
Year:	1957
Document Type:	BMRA
Issuing Agency:	U.S. Dept. of the Interior, Bureau of Mines,
SUDOC:	I 28.23:5318
Series:	Report of investigations / United States Department of the Interior, Bureau of Mines ;
Report Number:	5318
Subjects:	Coal mine accidents
	Mine explosions
Link:	https://hdl.handle.net/2027/mdp.39015077554072