TY  - BOOK
AU  - Alexander, Martin.
TI  - Ecological constraints on nitrogen fixation in agricultural ecosystems
KW  - NitrÃ³geno
KW  - FijaciÃ³n
KW  - Rhizobium
N1  - Sobretiro de : Advances Microbial Ecology 8:163-183, 1985
ER  -