แซ่โง้ว สิริวรรณ. “Development of ‘是’ Copula Verb and Copula Construction in Chinese”. Journal of the Faculty of Arts, Silpakorn University 40, no. 2 (May 14, 2019): 149–176. Accessed April 29, 2024. https://so04.tci-thaijo.org/index.php/jasu/article/view/189828.