INDRZEJCZAK, A. Admissibility of cut in congruent modal logics. Logic and Logical Philosophy, [S. l.], v. 20, n. 3, p. 189–203, 2011. DOI: 10.12775/LLP.2011.010. Disponível em: https://apcz.umk.pl/LLP/article/view/LLP.2011.010. Acesso em: 7 dec. 2021.