SUCHENEK, Marek. On Undecidability of Non-monotonic Logic. Studia Informatica. System and information technology, [S. l.], v. 7, n. 1-2, p. 127–132, 2006. Disponível em: https://czasopisma.uws.edu.pl/studiainformatica/article/view/2856. Acesso em: 21 nov. 2024.