EPTD Discussion Paper no. 109, Washington, DC: International Food Policy Research Institute (IFPRI), Environment and Production Technology Division (EPTD), September 2003

Also Chapter in Rice Science: Innovations and Impact for Livelihood; Proceedings of the International Rice Research Conference, September 16-19, 2002, Beijing, China, eds. T.W. Mew, D.S. Brar, S. Peng, D. Dawe and B. Hardy, (Beijing, China: International Rice Research Institue (IRRI), Chinese Academy of Engineering and Chinese Acadmey of Agricultural Sciences, 2003), pp. 807-828