Development of a successful multiple percussion drill carriage

Author:	Ballinger, Homer J.
Year:	1950
Document Type:	BMRA
Issuing Agency:	U.S. Dept. of the Interior, Bureau of Mines,
SUDOC:	I 28.23:4625
Series:	Report of investigations / Bureau of Mines ;
Report Number:	4625
Subjects:	Oil-shales
	Drilling and boring machinery
Link:	https://hdl.handle.net/2027/mdp.39015078487157