• publisher: Pittsburgh, Pa. : U.S. Dept. of the Interior, Bureau of Mines
  • creator: Dalzell, Robert S Curth, Ernest A
  • contributor: Curth, Ernest A.
  • Keyword: Ground control (Mining) Coal mines and mining Safety measures.
  • years: 1985.
  • pages: 29 p. :
  • class: TN295 TN288
  • download: pdf file