Leerodanawutikun C, Tipmontien K, Phiukhao S. Inequality of old-age pension in the social security system of self-employed insured persons. JDSC [internet]. 2025 Mar. 20 [cited 2026 Oct. 13];12(1):355-68. available from: https://so03.tci-thaijo.org/index.php/rdirmu/article/view/281296