Lekkoksung, N., H. Sanpan, and S. Lekkoksung. “Characterizations of Some Regularities in Ordered Ternary Semigroups in Terms of Fuzzy Subsets”. Communications in Mathematics and Applications, vol. 12, no. 2, June 2021, pp. 325-33, doi:10.26713/cma.v12i2.1489.