1. Feneuille, S., Schweighofer, M.G.: J. Phys. (Paris) V36, 781 (1985)
2. Whitley, R.M., Stroud, C.R., Jr.: Phys. Rev. A14, 1498 (1976)
3. Cohen-Tannoudji, C., Reynaud, S.: J. Phys. B10, 2311 (1977)
4. Agostini, P., Georges, A.T., Wheatley, S.E., Lambropoulos, P., Levenson, M.D.: J. Phys. B: At. Mol. Phys.11, 1733 (1978)
5. Delone, N.B., Krainov, V.P.: Atoms in strong light fields. In: Springer Series in Chemical Physics. Vol. 28, pp. 89?91. Berlin, Heidelberg, New York, Tokyo: Springer 1985