W. I. Skrypnik, “Mechanical systems with singular equilibria and the Coulomb dynamics of three charges”, Ukr. Mat. Zhurn., vol. 70, no. 4, pp. 519–533, Apr. 2018, Accessed: Dec. 05, 2025. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/1573