Cheat Sophal, Khieu Borin and Preston T R 2010 Effects of supplements of water hyacinth and cassava hay on the performance of local “Yellow” cattle fed a basal diet of rice straw.  (Editor: Reg Preston) International Conference on Livestock, Climate Change and Resource Depletion, Champasack University, Pakse, LAO PDR, 9-11 November 2010 . httm://www.mekarn.org/workshops/pakse/html/sophal.htm