1. P. A. Apanasevich, Principles of the Theory of Light Interaction with Matter [in Russian], Nauka i Tekhnika, Minsk (1977).
2. J. R. Shen, Principles of Nonlinear Optics, J. Wiley and Sons, New York (1984).
3. D. Cotter, D. C. Hanna, and R. Wyatt, Appl. Phys., 8, 333–340 (1975).
4. K. S. Repasky and J. L. Carlsten, Phys. Rev. A: At., Mol., Opt. Phys., 54, 4528–4533 (1996).
5. P. A. Apanasevich and G. I. Timofeeva, Zh. Prikl. Spektrosk., 74, No. 2, 230–236 (2007).