Donphanmuang, Oradee, Wanida Pharanat, and Prayong Hatthaprom. 2025. “Development of collaborative learning activities using CIRC techniques with exercises to promote the ability to pronounce diphthongs for grade 3 students”. Journal for Developing the Social and Community 12 (3). Bangkok, Thailand:1-16. https://so03.tci-thaijo.org/index.php/rdirmu/article/view/288536.