CHÂU, Trần Thọ. Fuzzy Petri nets and a necessary condition of law of contraposition in fuzzy logic. <b>Journal of Computer Science and Cybernetics</b>, <i>[S. l.]</i>, v. 16, n. 3, p. 23–31, 2013. DOI: 10.15625/1813-9663/16/3/2904. Disponível em: https://jcc.vast.vn/jcc/article/view/2904. Acesso em: 4 nov. 2025.