Hoang Nghia Duyet, Truong Thi Thuan and Nguyen Duc Son 2006: 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 "Forages for Pigs and Rabbits" MEKARN-CelAgrid, Phnom Penh, Cambodia, 22-24 August,  2006. Article # 16. Retrieved, from http://www.mekarn.org/proprf/duyet.htm