KARPENKO, O. V.; KRAVETS, V. I.; STANZHITSKII, A. N. Oscillation of solutions of the second-order linear functional-difference equations. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 65, n. 2, p. 226–235, 2013. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/2414. Acesso em: 5 dec. 2025.