Ditthakit, Parichart, and Junya Singkham. “The Use of Modified Leonardite for Water Convolvulus Growing in Clay Soil”. STOU Journal of Agriculture (Online) 1, no. 1 (June 1, 2019): 47–56. Accessed May 17, 2024. https://so01.tci-thaijo.org/index.php/stouagjournal/article/view/246567.