Ratanopad Suwnalee, S., J. Somard, and P. Pommarag. “The Relationship Between Toponym and Geographical Characteristics for Places through Isan Folk Songs”. Journal of the Faculty of Arts, Silpakorn University, vol. 43, no. 1, June 2021, pp. 179-94, https://so04.tci-thaijo.org/index.php/jasu/article/view/252061.