Nilwan, D. (2019). The Competency Gap of Travel Agents for Halal Tourism: A Case Study of Muang Chiang Mai District, Chiang Mai Province. University of the Thai Chamber of Commerce Journal Humanities and Social Sciences, 37(4), 20–34. Retrieved from https://so06.tci-thaijo.org/index.php/utccjournalhs/article/view/178253