1. L. D. Landau and E. M. Lifshits, Course of Theoretical Physics, Vol. 3: Quantum Mechanics: Non-Relativistic Theory (Nauka, Moscow, 1989; Pergamon, New York, 1977).
2. A. V. Burenin, Symmetry of Intramolecular Quantum Dynamics (IPF RAN, Nizhny Novgorod, 2012; Walter de Gryuter, Berlin, 2012).
3. A. S. Davydov, Quantum Mechanics (Nauka, Moscow, 1973) [in Russian].
4. P. A. Braun and A. A. Kiselev, Introduction to the Theory of Molecular Spectra (LGU, Leningrad, 1983) [in Russian].
5. I. B. Bersuker and V. Z. Polinger, Vibronic Interactions in Molecules and Crystals (Springer, Berlin, Heidelberg, etc., 1989).