Sampling and exploration by means of hammer drills

Author:	Knaebel, John B.
Year:	1932
Document Type:	USBI
Issuing Agency:	U.S. Dept. of Commerce, Bureau of Mines,
SUDOC:	C 22.11:6594
Series:	Information circular / United States Department of the Interior, Bureau of Mines ;
Report Number:	6594
Subjects:	Power tools
	Pneumatic drills
Link:	https://hdl.handle.net/2027/mdp.39015078515254