TUNC, Cemil. Instability to vector lienard equation with multiple delays. CUBO, A Mathematical Journal, [S. l.], v. 17, n. 1, p. 1–9, 2015. DOI: 10.4067/S0719-06462015000100001. Disponível em: https://cubo.ufro.cl/index.php/cubo/article/view/1147. Acesso em: 13 oct. 2025.