1. V. S. Letokhov,Nonlinear Selective Photoprocesses in Atoms and Molecules [in Russian], Moscow (1983).
2. G. I. Bekov, A. T. Tursunov, G. Khasanov, and N. B. Éshkobilov,Opt. Spektrosk.,62, 273–278 (1987).
3. A. T. Tursunov, N. B. Éshkobilov, and A. T. Khalmanov,Opt. Spektrosk.,68, 507–511 (1990).
4. A. T. Tursunov, N. B. Éshkobilov, and A. T. Khalmanov, in:Abst. XX All-Union Congr. on Spectroscopy, Kiev, September 1988 [in Russian], Pt. 1 (1988), p. 110.
5. G. C. Turk, J. R. De Vol, and J. C. Travis,Anal. Chem.,54, 643–645 (1982).