Ellis, Treenuch, Artit Hutem, and Akgabutkhan Pathan. “Models for Calculation of Global Solar Radiation from Meteorological Data for Phetchabun Province”. Princess of Naradhiwas University Journal 11, no. 2 (April 2, 2019): 132–141. accessed September 17, 2026. https://li01.tci-thaijo.org/index.php/pnujr/article/view/123146.