1. W. Jamroz, B. Stoicheff: Progress in Optics 20, 326 (North-Holland, Amsterdam 1983) (and references therein)
2. C.R. Vidal: In Tunable Lasers, ed. by I.F. Mollenhauer, J.C. White, Topics Appl. Phys. 59 (Springer, Berlin, Heidelberg 1987)
3. R. Hilbig, G. Hilber, R. Wallenstein: Comments At. Mol. Phys. 18, 157 (1986) (and references therein)
4. G. Hilber, A. Lago, R. Wallenstein: J. Opt. Soc. Am. B 4, 1753 (1987)
5. A. Lago, G. Hilber, R. Wallenstein: Phys. Rev. A 36, 3827 (1987)