มาแก้ว ฉัตรชัย. 2015. “Development of sealant service in primary school students Phrompiram hospital, Phitsanulok province, Thailand during educational years 2006-2014”. Thai Dental Public Health Journal 20 (3). Bangkok, Thailand:17-27. https://he02.tci-thaijo.org/index.php/ThDPHJo/article/view/150932.