SKRYPNIK, W. I. Periodic Coulomb dynamics of three equal negative charges in the field of fixed four equal positive charges. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 73, n. 12, p. 1698–1713, 2021. DOI: 10.37863/umzh.v73i12.6550. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/6550. Acesso em: 13 dec. 2025.