1. See review articles by various authors in: Magnetism, ed. H. Suhl, Vol. V. New York and London: Academic Press 1973
2. Ruderman, M.A., Kittel, C.: Phys. Rev.96, 99 (1954) Kasuya, T.: Progr. Theor. Phys. (Kyoto)16, 45 (1956) Yosida, K.: Phys. Rev.106, 893 (1957)
3. See recent review articles on Kondo systems with RE ions by: Maple, M.B., De Long, L.E., Sales, B.C. in: Handbook on the Physics and Chemistry of Rare Earths, ed. K.A. Gschneidner and LeRoy Eyring, forthcoming and: Steglich, F. in: Festkörperprobleme (Advances in Solid State Physics) Vol. XVII, p. 319, J. Treusch (ed.), Braunschweig: Vieweg 1977
4. van Dam, J.E., Gubbens, P.C.M., van dem Berg, G.J.: Physica62, 389 (1972)
5. Steiner, P., Hüfner, S.: Phys. Rev. B9, 4038 (1974); Phys. Rev. B12, 842 (1975) Steiner, P., Perez-Ramirez, J.G.: J. Phys. F: Metal Phys.7, 1573 (1977)