IVOCHKINA, N.; LADYZHENSKAYA, O. Estimation of the second derivatives for surfaces evolving under the action of their principal curvatures. Topological Methods in Nonlinear Analysis, [S. l.], v. 6, n. 2, p. 265–282, 1995. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.1995.045. Acesso em: 22 lip. 2024.