1. Ringbom A and Wännien E in Kolthoff IM, and Elving PJ (1979) Treatise on Analytical Chemistry, Part I, Vol. 2, Wiley New York.
2. Buffle J (1988) Complexation Reactions in Aquatic Systems, Wiley New York
3. Huber W (1980) WAF 1, 8
4. Debye P and Hückel E (1923) Phys. Z. 24, 185
5. Davison W Elektroanal J (1987) Chem 87: 395.