00353    a2200133   4500020001500000082001300015100001700028245004600045260005000091300002000141650001200161650002700173700001900200  a812191681X  a577bVER  aVerma, P. S.  aConcept of ecologybenvironmental biology  aNew DelhibS. Chand & Company Ltdc1998g1999  avii,264p.c24cm  aEcology  aLife sciences  Biology  aAgarwal, V. K.