R. Thangappan. “On $\beta^*$-Open and $\beta^*$-Closed Sets in Fuzzy Topological Space”. Malaya Journal of Matematik 9, no. 01 (January 1, 2021): 291–294. Accessed July 16, 2024. https://www.malayajournal.org/index.php/mjm/article/view/1019.