DobrynskiiV. A. “On Synchronization of Symmetrically Perturbed Systems With Quadratic Nonlinearity”. Ukrains’kyi Matematychnyi Zhurnal 51, no. 11 (November 25, 1999): 1569–1573. Accessed November 22, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/4759.