GULOV, Kh. M.; PERESTYUK, N. A. Integral sets of systems of difference equations. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 45, n. 12, p. 1613–1621, 1993. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/5968. Acesso em: 5 dec. 2025.