FREITAG, Wolfgang; ZINKE, Alexandra. The theory of form logic. Logic and Logical Philosophy, [S. l.], v. 21, n. 4, p. 363–389, 2012. DOI: 10.12775/LLP.2012.017. Disponível em: https://apcz.umk.pl/LLP/article/view/LLP.2012.017. Acesso em: 8 jul. 2025.