1. J.C. Camparo: Contemp. Phys. 26, 443 (1985)
2. C.E. Wieman, L. Hollberg: Rev. Sci. Instrum. 62, 1 (1991)
3. See Ref. 2 and references therein
4. B. Scheumann, D. Meschede, T.W. Hänsch, J.L. Hall: Proc. IQEC-90, Opt. Soc. Am. (1990)
5. L. Hollberg, V. Velichansky, R. Ellingsen, A. Zibrov, M. Tino: XIV Int'l Conf. on Coherent and Nonlinear Optics, Leningrad (1991, unpublished);