1. The Chemistry of Imperfect Crystals, North-Holland Publ. Co., Amsterdam 1964.
2. , and , Papers of the Tallinn Technical University No. 404, Tallinn 1976 (p. 9).
3. and , in: Proc. IV. All-Union Conf. Physics, Chemistry, and Technical Application of AIIBVI Compounds, Odessa 1976 (p. 3).
4. , , and , see [3] (p. 3).