IAMPAN, A. Fuzzification of Ideals and Filters in $\Gamma$-Semigroups. Armenian Journal of Mathematics, Yerevan, Armenia, v. 4, n. 1, p. 44–48, 2012. Disponível em: http://test.armjmath.sci.am/index.php/ajm/article/view/83. Acesso em: 9 may. 2026.