TY  - BOOK
AU  - Ayanaba, A., ed.
AU  - Dart, P J, ed.
TI  - Biological nitrogen fixation in farming systems of the tropics
SN  - 0471994995
U1  - 631.9/AYA 
PY  - 1977///
CY  - New York
PB  - John Wiley and Sons
KW  - cropping system
KW  - nitrogen fixation
ER  -