[1]
E. P. Belan, “Global solutions and invariant tori of difference-differential equations”, Ukr. Mat. Zhurn., vol. 49, no. 1, pp. 11–24, Jan. 1997, Accessed: Dec. 05, 2025. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/4983