SkrypnikW. I. “Periodic Coulomb Dynamics of Three Equal Negative Charges in the Field of Fixed Four Equal Positive Charges”. Ukrains’kyi Matematychnyi Zhurnal 73, no. 12 (December 17, 2021): 1698 - 1713. Accessed November 21, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/6550.