1. C. Borghese, R. Comsi, P. De Gasperis and R. Tappa, Appl. Phys. Lett. 33, 344 (1978).APPLAB0003-6951
2. R. LeCraw, E. Gyorgy, R. Pierce, J. Nielsen, S. Blank, D. Miller and R. Wolfe, Appl. Phys. Lett. 31, 243 (1977).APPLAB0003-6951
3. L. Hsia, P. Wigen, P. de Gasperis and C. Borghese, J. Appl. Phys. 50, 7835 (1979).JAPIAU0021-8979
4. W. Stacy and C. Rooymans, Solid State Comm., 9, 2005 (1971).
5. W. Wolf, Phys. Rev. 108, 1152 (1957).PHRVAO0031-899X