β€œOn Existence of a Smooth Bounded Semiinvariant Manifold for a Degenerate Nonlinear System of Difference Equations in the Space $\mathfrak{m}$”. Neliniini Kolyvannya 6, no. 3 (September 29, 2003): 378–400. Accessed April 12, 2026. https://nosc.imath.kiev.ua/index.php/nosc/article/view/275.