1. S. N. Bagayev, V. S. Egorov, I. B. Mekhov, et al., in Proceedings of III International Symposium on Modern Problems of Laser Physics, MPLP 2000, Novosibirsk, 2000, p. 147.
2. S. Prasad and R. L. Glauber, Phys. Rev. A 61, 063814 (2000).
3. M. Fleischhauer, M. D. Lukin, A. B. Matsko, and M. O. Scully, Phys. Rev. Lett. 84, 3558 (2000).
4. V. V. Vasil’ev, V. S. Egorov, A. N. Fedorov, and I. A. Chekhonin, Opt. Spektrosk. 76, 146 (1994) [Opt. Spectrosc. 76, 134 (1994)].
5. W. Gawlik, R. Shuker, and A. Gallaher, Phys. Rev. A 64, 021801 (2001).