1. I. B. Bersuker:Zum. ’Eksp. Teor. Fiz.,43, 1315 (1962) (English translation:Sov. Phys. JETP,16, 933 (1963)).
2. I. B. Bersuker andB. G. Vekhter:Fiz. Tverd. Tela,5, 2432 (1963) (English translation:Sov. Phys. Sol. State,5, 1772 (1964)).
3. I. B. Bersuker andB. G. Vekhter:Phys. Stat. Solidi,16, 63 (1966).
4. F. S. Ham:Optical Properties of Ions in Crystals, edited byH. M. Crosswhite andH. W. Moos (New York, N. Y., 1967).
5. F. S. Ham:Jahn-Teller Effects in Electron Paramagnetic Resonance Spectra, edited byS. Geschwind (New York, N. Y., 1972).