Sihathep, Noukai, Vonvalay Inbounmy, and Chanthasone Vannavong. 2018. “Behavior and Willingness to Pay of Foreign Tourists for the Fee to Visit the Vat Phou Champasak World Heritage ”. Champasack University Scientific Journal 3 (3):50-58. http://cu-journal.com/index.php/files/article/view/25.