1. B. A. Zon, N. L. Manakov, and L. P. Rapoport, Multiphoton Processes in Atoms (Atomizdat, Moscow, 1978) [in Russian].
2. V. A. Davydkin, V. D. Ovsyannikov, and B. A. Zon, Laser Phys. 5(3), 449 (1993).
3. M. A. Preobrazhenskii, Opt. Spektrosk. 77(2), 559 (1994).
4. M. A. Preobrazhenskii and E. V. Zhnova, Opt. Spektrosk. 79(2), 200 (1995).
5. A. Khemli and M. Geogenana, Scientific Basics of Nanotechnologies and New Instruments, Ed. by R. Kelsall (Intellekt, Dolgoprudnyi, 2011) [in Russian].