Alain, K. M., K. M. Nathanael, and M. M. Rostin. “Integrating Fuzzy Concepts to Design a Fuzzy Data Warehouse”. International Journal of Computer (IJC), vol. 27, no. 1, Oct. 2017, pp. 112-3, https://ijcjournal.org/index.php/InternationalJournalOfComputer/article/view/1072.