Koochakpoor, T. “Fuzzy Hyper Pseudo BCK-Ideals of Hyper Pseudo BCK-Algebras”. Jordan Journal of Mathematics and Statistics 15, no. 3 (January 14, 2023): 381–398. Accessed September 18, 2024. https://jjms.yu.edu.jo/index.php/jjms/article/view/Nom1.