International Journal of Bifurcation and Chaos in Applied Sciences and Engineering (Internat. J. Bifur. Chaos Appl. Sci. Engrg.) (20240101), 34, no.~5, Paper No 2430011, 11~pp. ISSN: 0218-1274 (print).eISSN: 1793-6551.
Subject
37 Dynamical systems and ergodic theory -- 37J Finite-dimensional Hamiltonian, Lagrangian, contact, and nonholonomic systems 37J40 Perturbations, normal forms, small divisors, KAM theory, Arnolʹd diffusion