01061nam 2200325Ka 450 991069645730332120080306140916.0(CKB)5470000002378268(OCoLC)212914212(EXLCZ)99547000000237826820080306d1995 ua 0engtxtrdacontentcrdamediacrrdacarrierImproving the performance of longwall gob gas ventholes[electronic resource]Washington, DC :Bureau of Mines, U.S. Dept. of the Interior,[1995]2 unnumbered pages digital, PDF fileTechnology news ;no. 448Title from title screen (viewed on Mar. 6, 2008)."March 1995."Longwall miningUnited StatesLongwall miningUnited States.Bureau of Mines.GPOGPOBOOK9910696457303321Improving the performance of longwall gob gas ventholes3135177UNINA