PELYUKH, G. P. Solutions of systems of nonlinear difference equations that are continuous and bounded on the entire real axis and their properties. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 50, n. 12, p. 1636–1645, 1998. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/4783. Acesso em: 11 apr. 2025.