Pratik Singh Thakur, Rohit Kumar Verma, and Rakesh Tiwari. “Operations on Multisets and Fuzzy Multisets”. International Journal of Mathematics And its Applications 11, no. 3 (August 9, 2023): 45–58. Accessed May 20, 2024. http://ijmaa.in/index.php/ijmaa/article/view/1198.