Longpichai, O. “Determinants of Adoption of Crop Diversification by Smallholder Rubber Producers in Southern Thailand: Implications on Natural Resource Conservation”. Kasetsart Journal of Social Sciences, vol. 34, no. 2, Aug. 2013, pp. 370-82, https://so04.tci-thaijo.org/index.php/kjss/article/view/246994.