KAJITANI, K.; YUZAWA, Y. The Cauchy problem for hyperbolic systems with Hölder continuous coefficients with respect to the time variable. ANNALI SCUOLA NORMALE SUPERIORE - CLASSE DI SCIENZE, [S. l.], v. 5, n. 4, p. 465-482, 2009. DOI: 10.2422/2036-2145.2006.4.03. Disponível em: https://journals.sns.it/index.php/annaliscienze/article/view/107. Acesso em: 20 feb. 2026.