1. W. Stumm, J. Morgan, Aquatic Chemistry, third ed., Wiley, New York, 1996, Ch. 6.
2. W. Lund, The Complexation of Metal Ions by Humic Substances in Natural Waters, NATO ASI Ser. G., Kluwer, Dordrecht, The Netherlands, 1990, pp. 23, 43.
3. Complexation Reactions in Aquatic Chemistry: An Analytical Approach;Buffle,1989
4. A.M. Mota, M.L.S. Gonçalves, Direct methods of speciation of heavy metals in natural waters, in: S. Caroli (Ed.), Element Speciation in Bioinorganic Chemistry, Wiley, New York, 1996, Ch. 2.
5. A. Tessier, D.R. Turner (Eds.), Metal Speciation and Bioavailability in Aquatic Systems, Wiley, New York, 1995, Chs 5–7.