1. R. W. James, “The crystalline state Vol. II” (G. Bell and Sons, London, 1965) 20et seq.
2. “International Tables for X-ray Crystallography Vol. III” (The Kynoch Press, 1962) 233, 236.
3. Y. Suwa, M. Inagaki, F. Nakakita, andS. Naka (to be published).
4. S. Naka (to be published).
5. H. Furuhashi, M. Inagaki, andS. Naka (to be published).