DUMNICKI, M. A combinatorial proof of non-speciality of systems with at most 9 imposed base points. Annales Universitatis Paedagogicae Cracoviensis Studia Mathematica, [S. l.], v. 8, p. 79–90, 2009. Disponível em: https://studmath.uken.krakow.pl/article/view/13261. Acesso em: 31 oct. 2026.