SHAHMORAD, S. Anisotropic Differential Operators with Parameters and Applications. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 66, n. 7, p. 983–1002, 2014. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/2193. Acesso em: 5 dec. 2025.