SZPOND, J. Some properties of analytic sets with proper projections. Annales Universitatis Paedagogicae Cracoviensis Studia Mathematica, [S. l.], v. 9, p. 143–150, 2011. Disponível em: https://studmath.uken.krakow.pl/article/view/13252. Acesso em: 29 oct. 2026.