O. O. Prishlyak, “Topological Equivalence of Morse–Smale Vector Fields with beh2 on Three-Dimensional Manifolds”, Ukr. Mat. Zhurn., vol. 54, no. 4, pp. 492–500, Apr. 2002, Accessed: Feb. 17, 2026. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/4087