BRYLL, G.; SOCHACKI, R. On a test concerning the notion of the set. Annales Universitatis Paedagogicae Cracoviensis Studia Mathematica, [S. l.], v. 3, p. 33–38, 2003. Disponível em: https://studmath.uken.krakow.pl/article/view/13463. Acesso em: 30 oct. 2026.