The Relation Between the Differentiability of Solution and Lower-order Terms of the Cauchy Problem for a Class of Weakly Hyperbolic Equations with Singular Coefficients. Journal of Partial Differential Equations, [S. l.], v. 4, n. 1, p. 45–56, 1991. Disponível em: https://gsp.tricubic.dev/jpde/article/view/3672. Acesso em: 15 mar. 2026.