Nguyen Thi Duong Huyen, Nguyen Xuan Trach and Preston T R 2010 Effects of graded levels of paddy rice supplemented to water spinach (Ipomoea aquatica) or sweet potato (Ipomoea batatas) vines as basal diets on feed utilization and growth of New Zealand White rabbits.  International Conference on Livestock, Climate Change and Resource Depletion (Editor: Reg Preston),  Champasack University, Pakse, LAO PDR, 9-11 November 2010.  httm://www.mekarn.org/workshops/pakse/html/huyen.hua.htm