1. Deer W A, Howie R A and Zussman J 1963Rock-forming Minerals Vol 1 (London: Longmans)
2. Dejai A 1978 Ph.D. thesis University of Leningrad
3. Goldanskii V I, Markov E F and Kharpov V V 1963aZh. Eksp. Teor. Fiz. 44 752
4. Goldanskii V I, Markov E F and Kharpov V V 1963bPhys. Lett. 3 344
5. Karyagin S V 1963Dokl. Akad Nauk SSSR 148 1102