BAZALII, B. V.; DEGTYAREV, S. P. On one boundary-value problem for a strongly degenerate second-order elliptic equation in an angular domain. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 59, n. 7, p. 867–883, 2007. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/3352. Acesso em: 5 dec. 2025.