1. Proc. Internal. Conf. Amorphous Semiconductors 1980, Kishinev 1980 (p. 150) (in Russian).
2. Structural modification of some glassy chalcogenides
3. and , Proc. Internat. Conf. Amorphous Semiconductors 1982, Bucharest 1982 (p. 208) (in Russian).
4. Proc. Internat. Conf. Amorphous Semiconductors 1984, Vol. 1, Gabrovo 1984 (p. 151) (in Russian).
5. and see [4] (p. 171).