Hoang Nghia Duyet, Truong Thi Thuan and Nguyen Duc Son 2005: Effects on sow reproduction and piglet performance of replacing soybean meal by a mixture of sweet potato leaves, water spinach and fresh cassava foliage in the gestation and lactation diets of Mong Cai and Yorkshire sows.  Workshop-seminar "Making better  use of local feed resources" (Editors: Reg Preston and Brian Ogle) MEKARN-CTU, Cantho, 23-25 May, 2005. Article # 41. Retrieved, from http://www.mekarn.org/proctu/duye41.htm