TY  - BOOK
AU  - Simmonds, N W  .
TI  - Principles of crop improvement / 
SN  - 0-582-407028
U1  - 633.0853 
PY  - 1979///
CY  - London : 
PB  - Longman Group Limited , 
KW  - Evolution of crops
KW  - Geuetic aspects
KW  - Plant breeding
KW  - Population and selection
ER  -