Taladngoen, U., N. Palawatwichai, and S. Phanseethong. “Undergraduates’ Ability to Identify the English Liquids /r/ and /l/ at Word-Initial”. Humanities and Social Sciences Journal of Pibulsongkram Rajabhat University, vol. 14, no. 1, Mar. 2020, pp. 307-20, https://so01.tci-thaijo.org/index.php/GraduatePSRU/article/view/223436.