Development of a rotary test drill

Author:	Wright, Fred D.
Additional Authors:	Brackel, Lewis H.
Year:	1952
Document Type:	BMRA
Issuing Agency:	U.S. Dept. of the Interior, Bureau of Mines,
SUDOC:	I 28.23:4864
Series:	Report of investigations / United States Department of the Interior, Bureau of Mines ;
Report Number:	4864
Subjects:	Mines and mineral resources
	Mineral industries
	Mining engineering
	Drilling and boring
Link:	https://hdl.handle.net/2027/mdp.39015078468835