00353    a2200133   4500020001500000082001500015100001700030245004000047260004600087300001600133650001500149650003600164650001900200  a8170416825  a363.7bTRI  aTrivedi R.N.  a  A texbook of enviromental science  aNew DelhibAnmol Publicationsc1993g1993  a410p.c21cm  aASSOCITION  aOTHER SOCIAL PROBLEMS & SERVICE  aSOCIAL SERVICE