ZHANG, B. Periodicity in Dissipative-Repulsive Systems of Functional Differential Equations. CUBO, A Mathematical Journal, [S. l.], v. 5, n. 2, p. 331–349, 2003. Disponível em: https://cubo.ufro.cl/ojs/index.php/cubo/article/view/1702. Acesso em: 20 may. 2024.