Chaiwuttisak, P. . . and Sringamdee, T. . . (2021) “The Development of a Recommender System for Online Travel Insurance by using Intuitionistic Fuzzy Sets based on Gray Relational Analysis”, Creative Business and Sustainability Journal. Bangkok, Thailand, 43(4), pp. 1–19. available at: https://so01.tci-thaijo.org/index.php/CBSReview/article/view/253693 (accessed: 9 December 2025).