KOVTONYUK, D. A.; PETKOV, I. V.; RYAZANOV, V. I. On the boundary behavior of solutions of the Beltrami equations. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 63, n. 8, p. 1078–1091, 2011. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/2786. Acesso em: 5 dec. 2025.