Coal-mine timbering
Subtitle: technical information for use in vocational classes
Contributors: Virgin, R. Z. (Robert Zerubabel); Giles, Nathan B. (Nathan Blaine), 1884-; United States. Bureau of Mines; United States. Federal Board for Vocational Education
Edition: 2d rev. ed.
Publisher: G.P.O.
Published: 1935
Place of publication: Washington
Language: eng
Number of pages: 100
Subjects: Mine timbering