Prom-in, T. “Sources of Funds of Candidates in the General Election in Suphan Buri Province, B.E. 2562”. King Prajadhipok’s Institute Journal, vol. 19, no. 2, Sept. 2021, pp. 121-46, https://so06.tci-thaijo.org/index.php/kpi_journal/article/view/248195.