Nilapun, Somsak, and Sompote Bovornsin. “Evaluation of immunization coverage in Burirum, Surin and Nakornrajasima Province, 1989”. Srinagarind Medical Journal 5, no. 2 (November 11, 2013): 134–140. accessed September 18, 2026. https://li01.tci-thaijo.org/index.php/SRIMEDJ/article/view/13523.