Kumduang, Thodsaporn, and Sorasak Leeratanavalee. “Regularity of Linear Hypersubstitutions for Algebraic Systems of Type \(((n),(m))\)”. Communications in Mathematics and Applications 10, no. 1 (March 31, 2019): 1–18. Accessed May 3, 2024. https://www.rgnpublications.com/journals/index.php/cma/article/view/1098.