Layegh, L., and B. Davvaz. “Fundamental Relation on Hyper BCI-Algebras”. Bulletin of the Karaganda University. Mathematics Series 123, no. 3 (September 30, 2026): 121–129. Accessed September 30, 2026. https://mts.buketov.edu.kz/mathematics-vestnik/article/view/858.