Dr.A.Punitha Tharani and V.Uma Maheswari. “Introduction to Symmetric Semigroups and Symmetric Semirings”. International Journal of Advanced Science and Technology 29, no. 9s (May 7, 2020): 1963 - 1971. Accessed July 18, 2024. http://sersc.org/journals/index.php/IJAST/article/view/14171.