PRABA, B.; CHANDRASEKARAN, V.M.; MANIMARAN, A. A COMMUTATIVE REGULAR MONOID ON ROUGH SETS. Italian Journal of Pure and Applied Mathematics, [S. l.], v. 31, p. 307–318, 2013. Disponível em: https://journals.uniurb.it/index.php/ijpam/article/view/6129. Acesso em: 26 jul. 2026.