000 00246nam a2200109Ia 4500
020 _a9788721915472
082 _a628
100 _aDUGGAL, K.N
245 _aELEMENTS OF ENVORONMENTAL ENGINEERING
260 _aNEW DELHI
_b S.CHAND
_c2011
942 _cBK
999 _c2826
_d2826