PIETRYGA, A. Two kinds of unexpected problems in writings on logic. Logic and Logical Philosophy, [S. l.], v. 15, n. 2, p. 155–162, 2006. DOI: 10.12775/LLP.2006.009. Disponível em: https://apcz.umk.pl/LLP/article/view/LLP.2006.009. Acesso em: 5 jul. 2024.