RAHAYU, Afifah; BAKAR, Nova Noliza. TINGKATAN SUBGRUP DARI SUBHIMPUNAN FUZZY. Jurnal Matematika UNAND, [S. l.], v. 5, n. 1, p. 74–81, 2016. DOI: 10.25077/jmu.5.1.74-81.2016. Disponível em: https://jmua.fmipa.unand.ac.id/index.php/jmua/article/view/203. Acesso em: 6 nov. 2026.