1. Mitani, T.; Koda, T.: Phys. Letters 43A, 137 (1973)
2. Mitani, T.;Koda, T.: Solid State Phys. (in Japanese) 9, July (1974), (in press)
3. Busch, G.; Guntherodt, G.; Wachter, P.: J. Physique 32, C1–924 (1971)
4. Yanase, A.; Kasuya, T Koda, T.: J. Phys. Soc. Japan 25, 1025 (1968)
5. Mitani, T.; Koda, T.: to be published.