1. T. L. SHAY and J. M. WERNIEK, ?Ternary Chalcopyrite Semiconductors: Growth, Electronic, Properties and Applications? (Pergamon Press, New York, 1976).
2. J. M. MEESE, J. C. MANTHURUTHIL and D. R. LOCKER,Bull. Amer. Phys. Soc. 20 (1975) 696.
3. H. HAHEN and G. STRICK,Naturwissen 54 (1967) 225.
4. J. L. SHAY, S. WANGER, K. BACHMAN, E. BUEHLER and M. M. KASPER, Proceedings of the 11th IEEE Photovoltaic Special Conference, Phoenix, Arizona, 1975, p. 503.
5. P. W. YU, Y. S. PARK, S. P. FAILE and J. E. EHRET,Appl. Phys. 46 (1975) 4865.