AL-HUSBAN, Abdallah; AMOURAH, Ala; JABER, Jamil J. Bipolar complex fuzzy sets and their properties. Italian Journal of Pure and Applied Mathematics, [S. l.], v. 43, p. 754–761, 2020. Disponível em: https://journals.uniurb.it/index.php/ijpam/article/view/7293. Acesso em: 6 nov. 2026.