Thongkamkaew, W., A. NaRanong, and A. Thepmongkol. “The Analysis of the Determinants that Affect Education Expenditure in Low Income Countries and Lower Middle Income Countries”. Parichart Journal, vol. 34, no. 1, Apr. 2021, pp. 176-91, https://so05.tci-thaijo.org/index.php/parichartjournal/article/view/240196.