Oleksandr Mykolayovych Sharkovs’kyi. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 74, n. 12, p. 1719–1722, 2023. DOI: 10.37863/umzh.v74i12.7404. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/7404. Acesso em: 9 dec. 2025.