Rotary drilling holes in coalbeds for degasification

Author:	Cervik, Joseph.
Additional Authors:	Fields, H. H., Aul, George N.
Year:	1975
Document Type:	BMRA
Issuing Agency:	U.S. Bureau of Mines,
SUDOC:	I 28.23:8097
Series:	Report of investigations - Bureau of Mines ;
Report Number:	8097
Subjects:	Degassing of coal
	Boring
	Mine safety
Link:	https://hdl.handle.net/2027/mdp.39015078475053