Li, Qingxia, and Xinyao Yang. “On Suprememum of a Set in A Dedikind Complete Topological Space”. JOURNAL OF ADVANCES IN MATHEMATICS 14, no. 2 (November 1, 2018): 8025–8029. Accessed April 29, 2024. https://rajpub.com/index.php/jam/article/view/7807.