Team, Support. “On Decompositions of Intra-Regular and Left Regular Ordered ?-Semigroups: Chong-Yih Wu”. Thai Journal of Mathematics 16, no. 3 (December 1, 2018): 599–611. Accessed May 6, 2024. https://thaijmath2.in.cmu.ac.th/index.php/thaijmath/article/view/817.