Drillability studies :percussive drilling in the field

Author:	Schmidt, Robert L.
Year:	1972
Document Type:	BMRA
Issuing Agency:	U.S. Dept. of Interior, Bureau of Mines,
SUDOC:	I 28.23:7684
Series:	Report of investigations / United States Department of the Interior, Bureau of Mines ;
Report Number:	7684
Subjects:	Tunneling
	Boring machinery
	Percussion drilling
Link:	https://hdl.handle.net/2027/mdp.39015078477984