Chhay Ty, Le Duc Ngoan and Le Dinh Phung 2012 Effect of fresh cassava leaves and water spinach as protein sources in diets on N and amino acid digestibility in growing crossbred pigs.   Proceedings of the International Conference "Livestock-Based Farming Systems, Renewable  Resources and the Environment", 6-9 June 2012, Dalat, Vietnam (Editors: Reg Preston and Sisomphone Southavong) http:/www.mekarn.org/workshops/dalat2012/html/chhay.htm