B. Somboonsuke, P. Prommee, P. Cherdchom, and J. Petcharat, “The Sustainable Livelihood of Rubber Small Holder: A Case Study of Rubber- Fruit Tree Farming System in Kao Phra Community, The Southern Thailand”, kasetsart J. Soc. Sci., vol. 24, no. 2, pp. 156–168, Jul. 2003.