Fresnel lens blind area viewers for improved mine equipment safety and productivity

Author:	Johnson, Guy A.
Year:	1983
Document Type:	USBI
Issuing Agency:	U.S. Dept. of the Interior, Bureau of Mines,
SUDOC:	I 28.27:8950
Series:	Information circular / U.S. Dept. of the Interior, Bureau of Mines ;
Report Number:	8950
Subjects:	Fresnel lenses
	Mining machinery--Blind-area viewers
Link:	https://hdl.handle.net/2027/mdp.39015078455378