MarchukN. A. and TeplinskyY. V. (2001) “On the Smoothness of the Invariant Torus of a Countable System of Difference Equations with Parameters”, Ukrains’kyi Matematychnyi Zhurnal, 53(9), pp. 1241-1250. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/4343 (Accessed: 22November2024).