1.
Marchuk NA, Teplinsky YV. On the Smoothness of the Invariant Torus of a Countable System of Difference Equations with Parameters. Ukr. Mat. Zhurn. [Internet]. 2001Sep.25 [cited 2024Dec.8];53(9):1241-50. Available from: https://umj.imath.kiev.ua/index.php/umj/article/view/4343