CHÂU, T. T. Fuzzy Petri nets and a necessary condition of law of contraposition in fuzzy logic. Journal of Computer Science and Cybernetics, [S. l.], v. 16, n. 3, p. 23–31, 2013. DOI: 10.15625/1813-9663/16/3/2904. Disponível em: https://vjs.ac.vn/index.php/jcc/article/view/2904. Acesso em: 2 may. 2024.