1. , , and , Proc. Internat. Conf. Phys. Semicond., Warsaw 1972, PWN, Warsaw 1972 (p. 944).
2. , , , , and , Proc. Internat. Conf. Phys. Semicond., Warsaw 1972, (p. 938).
3. , , and , Proc. Internat. Conf. Phys. Semicond., Stuttgart 1974, Ed. B. G. Teubner Verlagsgesellschaft, Stuttgart 1974 (p. 1166).