CHERNETSKII, V. A. Unimprovable estimates for solutions of a mixed problem for linear elliptic equations of the second order in a neighborhood of an angular point. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 49, n. 11, p. 1529–1542, 1997. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/5152. Acesso em: 11 apr. 2025.