1. Figielski, T., Vitusevitch, S.A., Makosa, A., Dobrowolski, W., Belyaev, A.E., Wosinski, T., Konakova, R.V., and Kravchenko, L.N. (1995) Solid State Commun.9493
2. Figielski, T., Makosa, A., Wosinski, T., Harness, P.C., and Singer, K.E. (1994) Solid State Commun. 91, 913.
3. Alves, E.S., Leadbeather, M.L., Eaves, L., Henini, M., and Hughes, O.H. (1989) Solid State Electron. 32, 1627
4. Sheard, F.W. and Tombs, G.A. (1988) Appl
Phys
Lett
52, 1228
5. Lerch, M.L.F., Martin, A.D., Simmonds, P.E., Eaves, L., and Leadbeather, M.L. (1994) Solid State Electron. 37, 961