NIKI, Satoru. Empirical Negation, Co-negation and Contraposition Rule I: Semantical Investigations. Bulletin of the Section of Logic, [S. l.], v. 49, n. 3, p. 231–253, 2020. DOI: 10.18778/0138-0680.2020.12. Disponível em: https://www.czasopisma.uni.lodz.pl/bulletin/article/view/5862. Acesso em: 8 dec. 2025.