1. E.N. Rizkalla, G.R. Choppin, in: K.A. Gschneider Jr., L. Eyring (Eds.), Handbook on the Physics and Chemistry of Rare Earths, vol. 18, ch. 127, Elsevier, 1994.
2. C. Musikas, in: Choppin, Navratil, Schulz (Eds.), Proc. Int. Symp., Honolulu, December 1984, World Scientific, Singapore.
3. Hard and Soft Acids and Bases
4. B. Weaver, in: Y. Marcus, J.A. Marinsky (Eds.), Ion Exchange and Solvent Extraction, vol. 6, ch. 4, Marcel Dekker, 1974.
5. K.L. Nash, in: K.A. Gschneider Jr., L. Eyring (Eds.), Handbook on the Physics and Chemistry of Rare Earths, vol. 18, ch. 121, Elsevier, 1994.