TY  - BOOK
AU  - D. P. CHAKRABORTY
TI  - BIOLOGY( N.C.E.R.T.) CLASS XI
SN  - 81-7450-064-2
U1  - 507/BIO 
PY  - 2002///
CY  - New Delhi
PB  - NATIONAL COUNSIL OF EDUCATIONAL RESEARCH AND TRAINING
KW  - PURE SCIENCE
ER  -