1. Adu-Gyamfi, J.J., Katayama, K., Gayatri Devi, Rao, T.P. and Ito, O. 1996. In Dynamics of Roots and Nitrogen in Cropping Systems of the Semi-Arid Tropics pp. 493–506 (eds O. Ito, C. Johansen, J.J. Gayamfi, K. Katayama, J.V.D.K. Kumar Rao and T.J. Rego). JIRCAS International Agriculture Series No.3. Tsukaba, Japan.
2. Afandi, F., Trabulsi, N. and Saxena, M.C. 1995. Biological nitrogen fixation by cool season food and feed legumes: impact on wheat productivity in Syria and Lebanon. Regional Soil Fertility Workshop, 19–23 November, 1995, Aleppo, Syria.
3. Arihara, J., Ae, N., and Okade, K. 1991. In Problems nutrition of grain legumes in the semi-arid tropics, pp. 183–194, (C. Johansen, K.K. Leer, and K.L. Sahrawat, eds.), ICRISAT, Patancheru, India.
4. Armstrong, E. L. 1986a. In: Proceedings of Symposium on N cycling in Agricultural Systems of Temperate Australia, Agricultural Research Institute, Wagga. 14–16 July, 1986. Aust. Soc. Soil Sci. (Ed. P.E. Bacon, J. Evans, R.R. Storrier and A.C. Taylor)
5. Armstrong, E. L. 1986b. In Proceeding of the Fourth International Lupin Conference, Geraldton, Western Australia. 15–22 August, 1986. International Lupin Association & Western Australia