TY  - BOOK
AU  - Verma. P.S.
TI  - Environmental biology (Principles of  ecology)
SN  - 81 219 0859 0
U1  - 574.5 
PY  - 2000///
CY  - New Delhi
PB  - S Chand and Company
KW  - Biology
KW  - Ecology
ER  -