Sritalalai, A., and C. Na Thalang. “The Significant Level of Marketing Mix Of Tourist Sites With Faith Naga Story In The Northeast Region (Udon Thani Province - Nong Khai Province - Bueng Kan Province - Nakhon Phanom Province) Thailand”. Rajamangala University of Technology Tawan-Ok Social Science Journal, vol. 9, no. 1, June 2020, pp. 143-57, https://so05.tci-thaijo.org/index.php/SocialJournal2rmutto/article/view/243803.