Ibrahim, Hariwan Zikri. “\(\delta^{*}\)-Open Sets and Relation Between Some Weak and Strong Forms of \(\delta^{*}\)-Open Sets in Topological Spaces”. Journal of Advanced Studies in Topology 6, no. 1 (June 1, 2022): 20–27. Accessed January 26, 2023. http://m-sciences.com/index.php/jast/article/view/169.