Maneekul, Thanes, Sophon Tanamai, Nipon Tangtham, and Peerasak Srinives. 2010. “Structures of the Agriculture Environmental System of Cassava in Khao Hin Sorn Royal Development Study Center Area”. Kasetsart Journal of Social Sciences 31 (2):220-30. https://so04.tci-thaijo.org/index.php/kjss/article/view/246674.