PELYUKH, G. P.; SAMOILENKO, A. M. Solutions of systems of nonlinear difference-differential equations of neutral type asymptotically bounded in the entire axis. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 46, n. 11, p. 1597–1601, 1994. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/5604. Acesso em: 5 dec. 2025.