Ultrasonic convergence measurements

Author:	McVey, James R.
Year:	1984
Document Type:	BMRA
Issuing Agency:	U.S. Dept. of the Interior, Bureau of Mines,
SUDOC:	I 28.23: 8893
Series:	Report of investigations / Bureau of Mines ;
Report Number:	8893
Subjects:	Mine roof control
	Coal mines and mining--Equipment and supplies--Safety measures
	Ultrasonic testing
Link:	https://hdl.handle.net/2027/mdp.39015078470054