Rueanphibun , A. . “GUIDELINES FOR THE MANAGING LEARNING ENVIRONMENT OF DISTRICT SERVICE UNITS, UTTARADIT SPECIAL EDUCATION CENTER”. Journal of MCU Nakhondhat, vol. 9, no. 8, Aug. 2022, pp. 146-61, https://so03.tci-thaijo.org/index.php/JMND/article/view/263276.