V. A. Dobrynskii, “On synchronization of symmetrically perturbed systems with quadratic nonlinearity”, Ukr. Mat. Zhurn., vol. 51, no. 11, pp. 1569–1573, Nov. 1999, Accessed: Apr. 09, 2025. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/4759