Hossain, M. A., and A. S. A. Noor. “Modular and Standard Filters of a Directed above Meet Semilattice”. Science & Technology Asia 12, no. 4 (October 29, 2015): 1–5. accessed April 22, 2026. https://ph02.tci-thaijo.org/index.php/SciTechAsia/article/view/41477.