Wichaksamethi, Onnarin, and Wasan Supsiriphan. “‘是’ As An Adverb”. Chophayom Journal 34, no. 3 (December 30, 2023): 288–303. accessed December 8, 2025. https://so01.tci-thaijo.org/index.php/ejChophayom/article/view/270021.