Florian Kurniadhi, Yosep Wahjudi, Abdul Rahman, Emil R. Kaburuan, Gunawan Wang, Sfenrianto. 2020. “Loyalty Point Reward System Using Blockchain : (Case Study in PT XYZ)”. International Journal of Control and Automation 13 (4), 245 -51. http://sersc.org/journals/index.php/IJCA/article/view/16074.