Kloyiam, Saichon. “Why Insured Persons under Social Security Act Article 40 Missed Paying Contribution: A Qualitative Study”. Journal of Health Systems Research 16, no. 3 (September 30, 2022): 390–406. accessed October 25, 2025. https://he04.tci-thaijo.org/index.php/j_hsr/article/view/3405.