Periodic Solutions of Nonlinear Wave Equations with Dissipative Boundary Conditions. Journal of Partial Differential Equations, [S. l.], v. 3, n. 1, p. 1–12, 1990. DOI: 10.4208/aamm.10-m1030. Disponível em: https://www.global-sci.com/index.php/jpde/article/view/3647. Acesso em: 5 dec. 2025.