High-order contact transformations of molecular Hamiltonians: general approach, fast computational algorithm and convergence of ro-vibrational polyad models / V. G. Tyuterev, S. A. Tashkun, M. Rey, A. V. Nikitin // Molecular physics. 2022. Vol. 120, № 15/16. P. e2096140. URL: http://vital.lib.tsu.ru/vital/access/manager/Repository/koha:001003258