GADJIEV, T. S.; GASIMOVA, E. R. On the smoothness of a solution of the first boundary-value problem for second-order degenerate elliptic-parabolic equations. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 60, n. 6, p. 723–736, 2008. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/3192. Acesso em: 5 dec. 2025.