Hoang Huong Giang, Le Viet Ly and Ogle B 2004: Digestibility of dried and ensiled sweet potato roots and vines and their effect on the performance and economic efficiency of F1 crossbred fattening pigs. Livestock Research for Rural Development. Vol. 16, Art. #50. Retrieved , from http://www.lrrd.org/lrrd16/7/gian16050.htm