BONDAR', O. P. On the number of critical submanifolds of a function on a manifold. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 45, n. 12, p. 1702–1705, 1993. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/5979. Acesso em: 5 dec. 2025.