000 00241nam a2200097Ia 4500
008 170501s9999 xx 000 0 und d
100 _aVenugupal Rao.P
245 _aPrin of Environment of Science & Engg
250 _a-
260 _bPHI
_aNew Delhi
_c2006
300 _a276
999 _c17161
_d17161