SamoilenkoM. V. (1995) “Investigation of a discrete dynamical system in a neighborhood of the invariant torus”, Ukrains’kyi Matematychnyi Zhurnal, 47(12), pp. 1676–1685. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/5561 (Accessed: 6October2024).