Investigation of stability of invariant sets for systems of difference equations by Lyapunov’s functions. Neliniini Kolyvannya, [S. l.], v. 3, n. 1, p. 3–6, 2000. Disponível em: https://twinhead.imath.kiev.ua/index.php/nosc/article/view/89. Acesso em: 22 jan. 2026.