SamoilenkoA. M. (1994) “On some problems in perturbation theory of smooth invariant tori of dynamical systems”, Ukrains’kyi Matematychnyi Zhurnal, 46(12), pp. 1665–1699. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/5577 (Accessed: 27July2024).