00438nam a22001457a 4500003001200000005001700012008004100029020001500070040001200085082001600097100001900113245013000132260001100262650001900273NUST - PNEC20170116180926.0150905b        xxu||||| |||| 00| 0 eng d  a0750647779  cLIBRARY  a628.922 GRO  aGroh, Heinrich  aExplosion protection : electrical apparatus and systems for chemical plants, oil and gas industry, coal miningcHeinrich Groh  cc.2004  aMine gasesxEE