Duangphonprom , Duangpon, Chayakan Ruangsuwan, and Pongphop Phoojomjit. 2026. “Guidelines for Developing Teachers’ Teamwork Competency Under the Mahasarakham Primary Educational Service Area Office 2”. Education journal Faculty of Education, Nakhon Sawan Rajabhat University 9 (3). Nakhon Sawan,Thailand:278-90. https://doi.org/10.2774.EDU2026.3.287471.