Team, Support. “Natural Partial Orders on the Semigroup of Binary Relations: C. Namnak, P. Preechasilp”. Thai Journal of Mathematics 4, no. 3 (December 1, 2006): 39–50. Accessed May 14, 2024. https://thaijmath2.in.cmu.ac.th/index.php/thaijmath/article/view/67.