HrodI. M., and KulikV. L. “On Local Perturbations of Linear Extensions of Dynamical Systems on a Torus”. Ukrains’kyi Matematychnyi Zhurnal 52, no. 2 (February 25, 2000): 282-287. Accessed September 1, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/4417.