On Continuity of the Invariant Torus for Countable System of Difference Equations Dependent on Parameters. Neliniini Kolyvannya, [S. l.], v. 4, n. 3, p. 316–325, 2001. Disponível em: https://twinhead.imath.kiev.ua/index.php/nosc/article/view/176. Acesso em: 22 jan. 2026.