Samanmit, P., J. Vongphet, K. Sittichok, S. Khawkomol, and S. Bhattrawuhichai. “Drought Analysis via the Use of Standardized Precipitation Evapotranspiration Index (SPEI): A Case Study of the Eastern Economic Corridor”. Science and Engineering Connect, vol. 46, no. 3, Sept. 2023, pp. 239-52, https://ph04.tci-thaijo.org/index.php/SEC/article/view/10171.