PRISHLYAK, O. O. Minimal Morse functions on a pair of manifolds. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 45, n. 1, p. 143–144, 1993. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/5795. Acesso em: 11 apr. 2025.