Team S. Regular Elements of the Variant Semigroups of Transformations Preserving Double Direction Equivalences: Winita Yonthanthum. Thai J Math [Internet]. 2018 Apr. 1 [cited 2024 Dec. 22];16(1):165-71. Available from: https://thaijmath2.in.cmu.ac.th/index.php/thaijmath/article/view/784