G. S. Voronov and N. B. Delone, Sov. Phys. JETP Lett.,1, 66 (1965).
J. Morelec, D. Normand, G. Mainfray, and C. Manus, Phys. Rev. Lett.,44, 1394 (1980).
P. Agostini, M. Clement, F. Fabre, and G. Petite, J. Phys.,14, 1491 (1981).
J. S. Bakos, Adv. Electron. Electron. Phys.,36, 57 (1974).
N. B. Delone, Sov. Phys. Usp.,18, 169 (1975).
P. Lambropoulos, Adv. At. Mol. Phys.,12, 87 (1976).
S. Edelstein, M. Lambropoulos, J. A. Duncanson, and R. S. Berry, Phys. Rev. A,9, 2459 (1974).
M. P. Strand, J. C. Hansen, R.-L. Chien, and R. S. Berry, Chem. Phys. Lett.,59, 205 (1978).
G. Leuchs, S. J. Smith, and H. Walther, in: Laser Spectroscopy IV, H. Walther and K. W. Rothe (eds.), Springer, Berlin-Heidelberg-New York (1979).
G. Leuchs, S. J. Smith, E. E. Khawaja, and H. Walther, Opt. Commun.,31, 313 (1979).
J. C. Hansen, J. A. Duncanson, R.-L. Chien, and R. S. Berry, Phys. Rev. A,21, 222 (1980).
H. Kaminski, J. Kessler, and K. J. Kollath, Phys. Rev. Lett.,45, 1161 (1980).
T. Hellmuth, G. Leuchs, S. J. Smith, and H. Walther, in: Lasers and Applications, W. O. N. Guimaraes, C.-T. Lin, and A. Mooradian (eds.), Springer, Berlin-Heidelberg (1981).
F. Fabre, P. Agostini, G. Petite, and M. Clement, J. Phys. B,14, L677 (1981).
G. Leuchs and S. J. Smith, J. Phys. B., in press.
V. L. Jacobs, J. Phys. B,5, 2257 (1972).
K. J. Kollath, J. Phys. B,13, 2901 (1980).
H. A. Bethe and E. E. Salpeter, Quantum Mechanics of One- and Two-Electron Atoms, Plenum Press, New York (1977), p. 296.
L. D. Landau and E. M. Lifschitz, Lehrbuch der Theoretischen Physic, Vol. 3, Akademie Verlag, Berlin (1979), p. 111.
P. Lambropoulos, Adv. At. Mol. Phys.,6, 145 (1976).
E. B. Alexandrov, Sov. Phys. Opt. Spectrosc.,16, 522 (1964).
T. Hellmuth, G. Leuchs, S. J. Smith, and H. Walther, Proceedings of the Second International Conference on Multi-Photon Processes, Budapest (1980).
E. C. Reifenstein, T. L. Wilson, B. F. Burke, P. G. Mezger, and W. J. Altenhoff, Astron. Astrophys.,4, 357 (1970).
A. V. Smith, J. E. M. Goldsmith, D. E. Nitz, and S. J. Smith, Phys. Rev. A,22, 577 (1980).
G. Leuchs, S. J. Smith, D. S. Elliott, and R. Roy, unpublished material.
H. A. Kramers, Philos. Mag.,44, 836 (1923).
D. H. Menzel and C. L. Pekeris, Mon. Not. R. Astron. Soc.,96, 77 (1935).
P. Lambropoulos, Appl. Opt.,19, 3926 (1980); (T. Olson and P. Lambropoulos, private communication).
B. Christensen-Dalsgaard and G. Leuchs, unpublished material.
W. Bother, Z. Phys.,26, 59 (1924).
M. O. Kruase, Phys. Rev.,177, 151 (1969).
H. Figger, G. Leuchs, R. Straubinger, and H. Walther, Opt. Commun.,33, 37 (1980).
K. R. Lang, Astrophysical Formulae, Springer, Berlin-Heidelberg-New York (1978).