01333nam 2200349Ka 450 991069689010332120080722085251.0(CKB)5470000002381977(OCoLC)234380231(EXLCZ)99547000000238197720080722d1973 ua 0engtxtrdacontentcrdamediacrrdacarrierGeologic factors causing roof instability and methane emission problems[electronic resource] the Lower Kittaning coalbed, Cambria County, Pa. /by C.M. McCulloch and Maurice Deul[Washington, D.C.?] :U.S. Dept. of the Interior, Bureau of Mines,[1973]ii, 25 pages digital, PDF fileReport of investigations ;7769Title from title screen (viewed on July 18, 2008).Geologic factors causing roof instability and methane emission problems Mine roof controlMine roof control.McCulloch C. M(Charles M.)1389497Deul Maurice1400549United States.Bureau of Mines.GPOGPOBOOK9910696890103321Geologic factors causing roof instability and methane emission problems3481157UNINA