1. Methods for the study of nitrogenase activity in field grown grasses;Abrantes;Bulletin International d'Informations Biologie du Sol,1975
2. Assaying nitrogenase (C2H2) actvity in the field;Balandreau;Bulletins from the Ecological Research Committee (Stockholm),1973
3. Acetylene reduction (nitrogen fixation) associated with corn inoculated with Spirillum;Barber;Applied and Environmental Microbiology,1976
4. Potential for nitrogen fixation in maize genotypes in Brazil;Von Bülow,1975
5. Nitrogen Fixation in Bacteria and Higher Plants;Burns,1975