Phongchan, Saranya, and Preeyanuch Honyam. “Regularity and Finiteness Conditions on Transformation Semigroups With Invariant Sets”. Thai Journal of Mathematics 21, no. 3 (September 30, 2023): 569–583. Accessed November 21, 2024. https://thaijmath2.in.cmu.ac.th/index.php/thaijmath/article/view/1528.