Chernetskii VA. Unimprovable estimates for solutions of a mixed problem for linear elliptic equations of the second order in a neighborhood of an angular point. Ukr. Mat. Zhurn. [Internet]. 1997Nov.25 [cited 2024Nov.24];49(11):1529–1542. Available from: https://umj.imath.kiev.ua/index.php/umj/article/view/5152