1. B. Marinkovic, V. Pejcev, D. Filipovic, et al., J. Phys. B 24, 1817 (1991).
2. S. J. Buckman and C. W. Clark, Rev. Mod. Phys. 66, 539 (1994).
3. P. D. Burrow, J. A. Michejda, and J. Comer, J. Phys. B 9, 3225 (1976).
4. S. M. Kazakov, Pis’ma Zh. Tekh. Fiz. 7, 900 (1981) [Sov. Tech. Phys. Lett. 7, 386 (1981)].
5. J. P. Sullivan, M. Moghbelalhossein, and S. J. Buckman, in Proceedings of the 20th International Conference on the Physics of Electronic and Atomic Collisions (XX ICPEAC), Vienna, 1997, p. TH014.