Ivochkina, N. and Ladyzhenskaya, O. (1995) “Estimation of the second derivatives for surfaces evolving under the action of their principal curvatures”, Topological Methods in Nonlinear Analysis, 6(2), pp. 265–282. Available at: https://apcz.umk.pl/TMNA/article/view/TMNA.1995.045 (Accessed: 22 July 2024).