Tang, Jian, Ze Gu, and Xiangyun Xie. “A Further Study on the Hyperideals of Ordered Semihypergroups”. Italian Journal of Pure and Applied Mathematics 43 (February 14, 2020): 447–470. Accessed November 6, 2026. https://journals.uniurb.it/index.php/ijpam/article/view/7327.