PETRUKHIN, Y. S5-Style Non-Standard Modalities in a Hypersequent Framework. Logic and Logical Philosophy, [S. l.], v. 31, n. 3, p. 427–456, 2021. DOI: 10.12775/LLP.2021.020. Disponível em: https://apcz.umk.pl/LLP/article/view/33865. Acesso em: 19 apr. 2024.