Limit Cycles in Piecewise Smooth Van der Pol Equations. Journal of Nonlinear Modeling and Analysis, [S. l.], v. 6, n. 3, p. 732–745, 2024. DOI: 10.12150/jnma.2024.732. Disponível em: https://global-sci.com/index.php/jnma/article/view/13762. Acesso em: 6 dec. 2025.