VLASENKO, I. Yu. Numerical Characteristics on the Set of Heteroclinic Points of Morse–Smale Diffeomorphisms on Surfaces. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 52, n. 10, p. 1415–1420, 2000. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/4546. Acesso em: 5 dec. 2025.