ZAKRZEWSKI, P. On the complexity of the ideal of absolute null sets. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 64, n. 2, p. 275–276, 2012. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/2574. Acesso em: 5 dec. 2025.