LEADER 01263oam 2200361 450 001 9910704546803321 005 20170517130156.0 035 $a(CKB)5470000002442237 035 $a(OCoLC)987379266 035 $a(EXLCZ)995470000002442237 100 $a20170517d2012 ua 0 101 0 $aeng 135 $aurbn||||||||| 181 $ctxt$2rdacontent 182 $cc$2rdamedia 183 $acr$2rdacarrier 200 00$aPillar recovery design, technologies, and procedures in roof control plan reviews 210 1$aArlington, Virginia :$cU.S. Department of Labor, Mine Safety and Health Administration,$d2012. 215 $a1 online resource (5 pages) 225 1 $aProcedure instruction letter ;$vno. I12-V-02 300 $a"Effective date: 02/16/2012; expiration date: 03/21/2014." 606 $aMine safety$zUnited States 606 $aBarrier pillars$xSafety measures 615 0$aMine safety 615 0$aBarrier pillars$xSafety measures. 712 02$aUnited States.$bMine Safety and Health Administration, 801 0$bGPO 801 1$bGPO 801 2$bGPO 906 $aBOOK 912 $a9910704546803321 996 $aPillar recovery design, technologies, and procedures in roof control plan reviews$93343490 997 $aUNINA