Prykarpatsky AK, Samoilenko AM, Timchishin OY. The Poincare-Mel’nikov geometric analysis of the transversal splitting of manifolds of slowly perturbed nonlinear dynamical systems. I. Ukr. Mat. Zhurn. [Internet]. 1993Dec.25 [cited 2024Nov.24];45(12):1668–1681. Available from: https://umj.imath.kiev.ua/index.php/umj/article/view/5975