Jomhataikool, Buntita, Kajornsak Faungnawakij, Sanchai Kuboon, W Kraithong, S Chutipaichit, Masayoshi Fuji, and Apiluck Eiad-Ua. “Effect of Humic Acid Extracted from Thailand’s Leonardite on Rice Growth”. Journal of Metals, Materials and Minerals 29, no. 1 (March 29, 2019). Accessed July 15, 2024. https://jmmm.material.chula.ac.th/index.php/jmmm/article/view/400.