[1] P. Agostini, F. Fabre, G. Mainfray, G. Petite, and N. K. Rahman, Phys. Rev. Lett. 42, 1127 (1979).
[2] P. Kruit, J. Kimman, H. G. Muller, and M. van der Wiel, Phys. Rev. A 28, 248 (1983).
[3] M. Mittleman, J. Phys. B 17, L351 (1984).
[4] E. Fiordilino and M. Mittleman, J. Phys. B 18, 4425 (1985).
[5] P. H. Bucksbaum, M. Bashkansky, R. R. Freeman, T. J. McIlrath, and L. F. DiMauro, Phys. Rev. Lett. 56, 2590 (1986).
[6] T. J. McIlrath, P. H. Bucksbaum, R. R. Freeman, and M. Bashkansky, Phys. Rev. A 35, 4611 (1987).
[7] R. R. Freeman, P. H. Bucksbaum, H. Milchberg, S. Darack, D. Schumacher, and M. E. Geusic, Phys. Rev. Lett. 59, 1092 (1987).
[8] R. M. Potvliege and R. Shakeshaft, Phys. Rev. A 38, 4597 (1988).
[9] P. Hansch, M. A. Walker, and L. D. V. Woerkom, Phys. Rev. A 57, R709 (1998).
[10] D.-S. Guo, Y.-S. Wu, and L. V. Woerkom, Phys. Rev. A 73, 023419 (2006).
[11] D.-S. Guo, J. T. Wang, and Y.-S. Wu, Phys. Rev. A 77, 025401 (2008).
[12] V. Schyia, T. Lang, and H. Helm, Phys. Rev. A 57, 3692 (1998).
[13] H. Rottke, J. Ludwig, and W. Sandner, J. Phys. B 29, 1479 (1996).
[14] R. Wiehle, B. Witzel, H. Helm, and E. Cormier, Phys. Rev. A 67, 063405 (2003).
[15] P. Agostini, A. Antonetti, P. Breger, M. Crance, A. Migus, H. G. Muller, and G. Petite, J. Phys. B 22, 1971 (1989).
[16] T. Shirai, J. Sugar, and A. Musgrove, "Wavelengths and energy levels for all spectra of argon (Ar I through Ar XVIII)" http://physics.nist.gov/PhysRefData/ASD/levels form.html (Apr. 20, 2009).
