TY  - BOOK
AU  - Verma, P.S. 
AU  -  Agarwal, V.K.
TI  - Environmental  Biology: principles of ecology
SN  - 81-219-0859-0
U1  - 577 
PY  - 2009///
CY  - Vidhyanagar
PB  - S. Chand
ER  -