R. THANGAPPAN. On $\beta^*$-open and $\beta^*$-closed sets in fuzzy topological space. Malaya Journal of Matematik, India, v. 9, n. 01, p. 291–294, 2021. Disponível em: https://www.malayajournal.org/index.php/mjm/article/view/1019. Acesso em: 16 jul. 2024.