1. Anon. 1975 Annual Report, International Institute of Tropical Agriculture, Ibadan, Nigeria. 219 p.
2. Bandoja, J. V., Altimirano, S. T. and Iswaran, V. 1974 Influence of lime pelleting of soybean and peanut on nodulation and yield in acid soils of Lipa. Philipp. J. Plant Ind.39, 21–24.
3. Bonnier, C. 1957 Symbiose Rhizobium-Légumineuses en région equatorial INÉAC Séries Scientifique72 67 p.
4. Bromfield, E. S. P. and Jones, D. Gareth 1979 The competitive ability and symbiotic effectiveness of doubly labelled antibiotic resistant mutants ofRhizobium trifolii. Ann. Appl. Biol.91, 211–219.
5. Dart, P. J., Day, J. M. and Harris, D. 1972 Assay of nitrogenase activity by acetylene reduction.In Use of Isotopes for study of Fertilizer Utilisation by Legume Crops. Joint Symposium IAEA/FAO, Vienna, Tech. Report No.149, 85–100.