1. Allaway, W.H. 1968. Adv Agron 20: 235–274.
2. Allison, J.D., and D.S. Brown. 1995. MintegA2/Prodefa2-A Geochemical Speciation Model and Interactive Processor. Soil Sci Soc Am, Madison, WI.
3. Bingham, F.T., G.A. Mitchell, R.J. Mahler, and A.L. Page. 1976. In Proceedings of the International Conference on Environmental Sensing and Assessment, vol 2. Inst Elec Electron Engrs, New York.
4. Bolan, N.S., R. Naidu, J.K. Syers, and R.W. Tillman. 1999. Adv
Agron 67: 87–140.
5. Boyd, G.E., J. Shubert, and A.W. Adamson. 1947. J Am Chem Soc 69: 2818–2829.