ALDASHEV, S. A. Well-posedness of many-dimensional Darboux problems for degenerating hyperbolic equations. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 46, n. 10, p. 1304–1311, 1994. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/5607. Acesso em: 6 dec. 2025.