HrodI. M. “On the Smoothness of Bounded Invariant Manifolds of Linear Inhomogeneous Extensions of Dynamical Systems”. Ukrains’kyi Matematychnyi Zhurnal 48, no. 1 (January 25, 1996): 136-139. Accessed November 24, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/5373.