1. D. Papoušek and M. R. Aliev, Molecular Vibrational/Rotational Spectra (Academia, Prague, 1982).
2. M. Herman and D. S. Perry, Phys. Chem. Chem. Phys. 15, 9970 (2013).
3. Yu. S. Makushkin and Vl. G. Tyuterev, Perturbation Methods and Effective Hamiltonians in Molecular Spectroscopy (Nauka, Novosibirsk, 1984) [in Russian].
4. A. A. Kiselev and A. V. Lyaptsev, Quantum Mechanical Perturbation Theory. Diagram Method (Leningr. Gos. Univ., Leningrad, 1989) [in Russian].
5. P. R. Bunker and P. Jensen, Molecular Symmetry and Spectroscopy (NRC Research Press, National Research Council Canada, 1998).