Kovtonyuk DA, Petkov IV, Ryazanov VI. On the boundary behavior of solutions of the Beltrami equations. Ukr. Mat. Zhurn. [Internet]. 2011 Aug. 25 [cited 2025 Dec. 5];63(8):1078-91. Available from: https://umj.imath.kiev.ua/index.php/umj/article/view/2786