Songdam K. THE TEACHER DEVELOPMENT MODEL IN PROBLEM-BASED LEARNING MANAGEMENT IS THE BASIS FOR THE DEVELOPMENT OF STUDENTS IN THE 21ST CENTURY, BANKHOKHWAN SCHOOL, NAKHON SI THAMMARAT PRIMARY EDUCATIONAL SERVICE AREA OFFICE 2. JSC [internet]. 2026 Mar. 31 [cited 2026 Oct. 14];10(3):389-400. available from: https://so06.tci-thaijo.org/index.php/JSC/article/view/292047