AGARWAL, P.; MANOJLOVIĆ, J. V. Asymptotic behavior of positive solutions of fourth-order nonlinear difference equations. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 60, n. 1, p. 8–27, 2008. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/3134. Acesso em: 6 dec. 2025.