1. Banus, M. D., Robinson, P. M.: J. Appl. Phys. 37 (1966) 3771.
2. Kerimov, I. C., Mamedov, K. K., Mekhtiev, M. I., Kostryukov, V. N.: Zh. Fiz. Khim. 45 (1971) 1969.
3. Mills, K. C.: Thermodynamic Data for Inorganic Sulphides, Selenides and Tellurides. London: Butterworth 1974.