MITROPOLSKIY, Yu. A.; KHOMA, N. H.; KHOMA, S. G. Smooth Solution of the Dirichlet Problem for a Quasilinear Hyperbolic Equation of the Second Order. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 52, n. 7, p. 931–935, 2000. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/4492. Acesso em: 14 apr. 2025.