TY  - BOOK
AU  - Verma, P. S.
TI  - Environmental biology: Principles of ecology 
SN  - 9788121908597
U1  - 333.6 
PY  - 2007///(1983)
CY  - New Delhi
PB  - S. Chand & Company Ltd.
KW  - Biology
KW  - Environment
ER  -