1. Memoirs of the Botanical Society of South Africa number;T. Arnold,1994
2. Bergersen, FJ., Turner, G.L., Amarger N., Mariotti, F., and Mariotti A 1986. Strain ofRhizobium lupini determines natural abundance of15N in root nodules ofLupinus spp.Soil Biology and Biochemistry 18: 97–101.
3. Brockwell, J. 1980. Experiments with crop and pasture legumes. Principles and practice. In:Methods for Evaluating Biological Nitrogen Fixation. Bergersen, F.J., ed. John Wiley and Sons Ltd., New York, pp. 417–488.
4. Elliott, G.N., Chen, W.-M., Bontemps, C., Chou, J.-H., Young, I.P.W., Sprent, J.I., and James, E.K. 2007. Nodulation ofCyclopia spp. (Leguminosae, Papilionoideae) byBurkholderia tuberum. Annals of Botany 100: 1403–1411.
5. Technical Communication;EJ. Hewitt,1966