Khotchaphet S. The Study of the Features of the Syymbols used to represent Thai Tones in Thai Language Teaching Textbooks for Foreigners at Fundamental to Basic Levels in different purposes of use. ARJLA [internet]. 2023 Dec. 20 [cited 2026 Sep. 24];18(2):169-96. available from: https://so04.tci-thaijo.org/index.php/larhcu/article/view/265864