BRZESKA, A. Density and capacity of balleans generated by filters. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 73, n. 4, p. 467–473, 2021. DOI: 10.37863/umzh.v73i4.648. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/648. Acesso em: 7 apr. 2025.