PAN, Wenjun; ZHAN, Jianming. ROUGH FUZZY GROUPS AND ROUGH SOFT GROUPS. Italian Journal of Pure and Applied Mathematics, [S. l.], v. 36, p. 617–628, 2016. Disponível em: https://journals.uniurb.it/index.php/ijpam/article/view/6554. Acesso em: 27 aug. 2026.