Traipak A, Sittilerd S. Learning Achievement of Writing Skills on Diphthong (ร หัน) by Using Instructional Package for Grade 3 Students of Settabutr Upathum School. RJPJ [Internet]. 2020 Feb. 25 [cited 2024 Apr. 24];14(32):37-49. Available from: https://so05.tci-thaijo.org/index.php/RJPJ/article/view/193780