Mandal, Sudin, Injamam Ul Karim, and Swapan Raha. “A Theory of Approximate Reasoning With Type-2 Fuzzy Set”. Journal of the Indonesian Mathematical Society 27, no. 1 (March 31, 2021): 9–28. Accessed April 18, 2024. http://jims-a.org/index.php/jimsa/article/view/905.