SHARKO, V. V. About Kronrod-Reeb graph of a function on a manifold. Methods of Functional Analysis and Topology, [S. l.], v. 12, n. 4, p. 389–396, 2006. Disponível em: https://zen.imath.kiev.ua/index.php/mfat/article/view/331. Acesso em: 16 dec. 2025.