GUO, Chengjun; O‘REGAN, Donal; AGARWAL, Ravi P. Existence of Periodic Solutions for a Class of Second-Order Neutral Differential Equations with Multiple Deviating Arguments. CUBO, A Mathematical Journal, [S. l.], v. 12, n. 3, p. 153–165, 2010. DOI: 10.4067/S0719-06462010000300010. Disponível em: https://cubo.ufro.cl/index.php/cubo/article/view/1397. Acesso em: 23 nov. 2025.