ธรรมสวัสดิ์ กิตติ. 2018. “Perception and Expectation of Social Insurance Fund Benefit of Informal Labors in Sam Phran Municipality Nakhon Pathom Province”. Integrated Social Science Journal, Mahidol University 1 (2):162-82. https://so02.tci-thaijo.org/index.php/isshmu/article/view/145989.