V. Subprabha, P. T. Infant Vijula, N. Durga Devi. A new closure operator via $(1,2) S_\beta$-open sets in bi-topological spaces. Malaya J. Mat. [Internet]. 2021 Jan. 1 [cited 2024 Jul. 16];9(01):1114-7. Available from: https://www.malayajournal.org/index.php/mjm/article/view/1232