M. AL-TAHAN; B. DAVVAZ. Refined neutrosophic quadruple (po-)hypergroups and their fundamental group. Neutrosophic Sets and Systems, [S. l.], v. 27, p. 138–153, 2019. Disponível em: https://fs.unm.edu/nss8/index.php/111/article/view/4219.. Acesso em: 13 sep. 2025.