Buangsuwan, C., Gesthong, T. and Uttaro, P. 2026. A MODEL OF STRENGTHENING TRANSFORMATIONAL LEADER ACCORDING TO THE FOUR PRINCIPLES SANGAHAVATTHU AMONG SCHOOL ADMINISTRATION UNDER THE NAKHON SAWAN PRIMARY EDUCATIONAL SERVICE AREA OFFICE 1 . Journal of Educational Review Faculty of Education in MCU. 13, 2 (Sep. 2026), 409–422.