BURSKII, V. P.; KIRICHENKO, E. V. On the dirichlet problem for an improperly elliptic equation. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 63, n. 2, p. 156–164, 2011. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/2707. Acesso em: 5 dec. 2025.