Kumduang, Thodsaporn, and Sorasak Leeratanavalee. “Regularity of Linear Hypersubstitutions for Algebraic Systems of Type \(((n),(m))\)”. Communications in Mathematics and Applications, vol. 10, no. 1, Mar. 2019, pp. 1-18, https://doi.org/10.26713/cma.v10i1.1098.