TY  - GEN
AU  - Verma , P.S.
AU  - Agarwal , V. K.
TI  - Environmental biology: principles of ecology
SN  - 8121908590
U1  - 577 
PY  - 2004///
CY  - New Delhi
PB  - S. Chand 
KW  - ENVIRONMENTAL BIOLOGY
ER  -