V. G. Samoilenko, “Integrability of nonlinear dynamical systems and differential geometry structures”, Ukr. Mat. Zhurn., vol. 45, no. 3, pp. 419–427, Mar. 1993, Accessed: Apr. 13, 2025. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/5824