Naritoom, C., Simsiriwong, K., Castella, J.-C., Trebuil, G., Saritniran, P. and Jantrprasert, J. 1991. On-Farm Diagnosis on the Intensification of Vegetable Cropping System for Exports to Improve the Sustainability of Small-Scale Farming Systems in Kamphaengsaen Area. Kasetsart Journal of Social Sciences. 12, 2 (Jul. 1991), 118–127.