TY  - BOOK
AU  - Metcalfe,Darrel S.
AU  - Elkins,Donald M  .
TI  - Crop production : principles and practices / 
SN  - 0023807105
U1  - 633 
PY  - 1972///
CY  - New York : 
PB  - Macmillan Publishing , 
KW  - FIELD CROPS
N1  - Include index
ER  -