StanzhitskiiA. N. “Investigation of Invariant Sets With Random Perturbations With the Use of the Lyapunov Function”. Ukrains’kyi Matematychnyi Zhurnal 50, no. 2 (February 25, 1998): 309–312. Accessed November 24, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/4965.