Detraksa, S., M. Waramit, and K. Kittipholwaiwingrob. “The Variation of Initial Consonant Blends /tr/ in Standard Thai as Spoken by Surat Thani Speech Community by social factors”. Journal of Humanities and Social Sciences Suratthani Rajabhat University, vol. 17, no. 2, Dec. 2025, pp. 118-37, https://so03.tci-thaijo.org/index.php/jhsc/article/view/289154.