PRISHLYAK, O. O. Conjugacy of Morse Functions on Surfaces with Values on a Straight Line and Circle. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 52, n. 10, p. 1421–1425, 2000. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/4547. Acesso em: 7 apr. 2025.