Samoilenko , A.M. (1992) “Investigation of a discrete dynamical system in the vicinity of quasi-periodic trajectory ”,
Ukrains’kyi Matematychnyi Zhurnal, 44(12), pp. 1702–1711. Available at:
https://umj.imath.kiev.ua/index.php/umj/article/view/8195 (Accessed: 10 April 2025).