The Periodic Boundary Problem and the Initial Value Problem for a Nonlinear System of Equations of Changing Type. Journal of Partial Differential Equations, [S. l.], v. 6, n. 4, p. 373–384, 2020. Disponível em: https://global-sci.com/jpde/article/view/3758. Acesso em: 4 mar. 2026.