TY  - GEN
TI  - Biological nitrogen fixation in farming system of the tropics
SN  - 0471994995
AV  - S481.B56 1977
PY  - 1997///
CY  - Toronto 
PB  - John Wiley and sons 
KW  - Agriculture
KW  - Tropics
KW  - Congresses
KW  - Nitrogen
KW  - Fixation
ER  -