@INPROCEEDINGS {AYANABA:1973, title = {Nodulation and nitrogen fixation in six grain legumes}, author = {Ayanaba, A. and Nangju, D. }, booktitle = {Proceedings of the First IITA Grain Legume Improvement Workshop, held at the International Institute of Tropical Agriculture, Ibadan, Nigeria, 29 October-2 November, 1973}, year = {1973}, month = {October}, pages = {198--204}, }