1. see e.g. Proceedings of the International Conference on Anomalous Rare Earth and Actinides ICAREA, Grenoble 1986, J. Magn. Magn. Mater.63 & 64 (1987);
2. Proceedings of the 18th Yamada Conference on Superconductivity in Highly Correlated Fermion Systems YCS, Sendai 1987. Physica B: (to be published)
3. Ohkawa, F.: J. Phys. Soc. Jpn.53, 1389 (1984)
4. Valls, O.T., Tesanovi?, Z.: Phys. Rev. Lett.53, 1497 (1984)
5. Fisk, Z., Stewart, G.R., Willis, J.O., Ott, H.R., Hulliger, F.: Phys. Rev. B30, 6360 (1984)