1. Ae, N., Otani,T., Makino, T. and Tazawa, J. 1996. Role of cell wall of groundnut roots in solubilizing sparingly soluble phosphorus in soil. Plant and Soil. 186: 197-204.
2. Aono, T. Kanada, N. Ijima, A. and Oyaizu, H. 2001. The Response of the Phosphate Uptake System and the Organic Acid Exudation System to Phosphate Starvation in Sesbania rostrata. Plant Cell Physiol. 42: 1253-1264.
3. Bhadoria, P. S., Dessougi, H. El., Liebersbach, H. and Claassen, N. 2004. Phosphorus uptake kinetics, size of root system and growth of maize and groundnut in solution culture. Plant and Soil. 262: 327-336.
4. Kretzschmar,R.M., Hafner, H., Bationo, A., and Marschner, H. 1991. Long- and short-term effects of crop residues on aluminium toxicity, phosphorus availability and growth of pearl millet in an acid sandy soil. Plant and Soil. 136: 215-223.
5. Otani, T. and Ae, N. 1996. I. Screening of Crops for Efficient P Uptake, Phosphorus （P） uptake mechanisms of crops grown in soils with low P status. Soil. Sci. Plant Nutr. 42: 155-163.