KHAMMESOUK, K., B. SIPHANTHONG, C. SENGDARA, and S. SIOUDOMPHAN. “The Impact of the Nam Et - Phou Louey National Park Conservation Project on the Economic Condition of the People in Hiem District, Houaphan Province”. Souphanouvong University Journal Multidisciplinary Research and Development, vol. 9, no. 2, May 2023, pp. 234-45, http://www.su-journal.com/index.php/su/article/view/397.