มาแก้ว ฉ. (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), 17–27. retrieved from https://he02.tci-thaijo.org/index.php/ThDPHJo/article/view/150932