TY  - BOOK
AU  - Bergersen, F.J.
TI  - Methods for evaluating biological nitrogen fixation
U1  - 581.138:631.46:661.5.001.4 M0 
PY  - 1980///
CY  - Chichester
PB  - John Wiley & Sons
KW  - F.J. Bergersen
KW  - Nitrogen fixation
ER  -