TAWFIQ, L. N. M.; SHIHAB, R. H. The Commutator of Two Fuzzy Subsets. Ibn AL-Haitham Journal For Pure and Applied Sciences, Baghdad, Iraq., v. 25, n. 2, 2017. Disponível em: https://jih.uobaghdad.edu.iq/index.php/j/article/view/643.. Acesso em: 24 nov. 2024.