1. Abdulla, M. M. F. and Fischbeck, G. (1978). Zeitschrift fur Acker — und Pflanzenbau 142(2): 81–91.
2. Ageeb, O. A. A. (1981). Annual Report of the Hudeiba Research Station 1976–77. Agricultural Research Corporation, Sudan, Wad Medani: ARC. pp. 1–18.
3. Bond, D. A., Lawes, D. A., Hawtin, G. C., Saxena, M. C. and Stephens, J. H. (1985). In Grain Legume Crops (eds R. J. Summerfield and E. H. Roberts), London: Collins, pp. 199–265.
4. Covell, S., Elus, R. H., Roberts, E. H. and Summerfield, R. J. (1986). Journal of Experimental Botany 37:705–715.
5. Dart, P. J., Islam, R. and Eaglesham, A. (1975). In Proceedings, International Workshop on Grain Legumes. Patancheru, A. P., India: ICRISAT. pp. 63–83.