Ketnoi, C. ., and S. . Soontayatron. “Correlation Between 7P’s Marketing Mix and Historical Tourism Promotion of Chan Palace in Phitsanulok Province”. Academic Journal of Thailand National Sports University, vol. 10, no. 2, May 2018, pp. 17-28, https://he02.tci-thaijo.org/index.php/TNSUJournal/article/view/248560.