ERTOLA BIRABEN, Rodolfo. J. Michael Dunn and Gary M. Hardegree, "Algebraic Methods in Philosophical Logic", Oxford Logic Guides, no. 41. Logic and Logical Philosophy, [S. l.], v. 14, n. 2, p. 265–267, 2005. DOI: 10.12775/LLP.2005.017. Disponível em: https://apcz.umk.pl/LLP/article/view/LLP.2005.017. Acesso em: 8 jul. 2025.