1. Adler, R., D. Janes, B.I. Hunsinger, S. Datta, 1981: Appl. Phys. Lett. 38, 102
2. Beyer, W., H. Mell, H. Overhof, 1981: J. de Physique (Paris) 42, C4–103
3. Beyer, W., J. Stuke, 1974: in Proc. 5th Int. Conf. on Physics of Amorphous and Liquid Semiconductors, ed. by J. Stuke, W. Brenig (Taylor and Francis, London) p. 251
4. Chen, K.J., H. Fritzsche, 1983: J. Non-Cryst. Sol. 58/60, 444
5. Cohen, J.D., 1984: in Semiconductors and Semimetals, Vol. 21c, ed. by R.K. Willardson, A.C. Beer (Academic Press, New York) p. 9