A flexible helical rock bolt /

Bibliographic Details

Main Author:	Babcock, Clarence O.
Corporate Author:	United States. Bureau of Mines
Format:	Government Document Book
Language:	English
Published:	[Washington] : Dept. of the Interior, Bureau of Mines, 1978.
Edition:	[Rev. ed.].
Series:	Report of investigations (United States. Bureau of Mines) ; 8300 r.
Subjects:	Rock bolts.