Team, Support. “Valuation $\tau$-Semirings and Valuation $\tau$-Ideals: S. Sangwirotjanapat, S. Tipyota, S. Pianskool”. Thai Journal of Mathematics 6, no. 3 (December 31, 2008): 93–102. Accessed May 17, 2024. https://thaijmath2.in.cmu.ac.th/index.php/thaijmath/article/view/138.