Jafarpour, Morteza, Fatemeh Jantani, and Violeta Leoreanu. “On Strongly Associative (Semi)Hypergroups”. Journal of the Indonesian Mathematical Society 23, no. 1 (December 24, 2017): 43–54. Accessed November 21, 2024. https://jims-a.org/index.php/jimsa/article/view/424.