ZARICHNYI, M. M. Еhird summer school algebra, analysis and topology. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 58, n. 1, p. 288–289, 2006. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/3442. Acesso em: 5 dec. 2025.