Pham Hong Son, Pham Quang Trung, Tran Quang Vui  and  Dinh Thi Bich Lan 2003: Preliminary research results on application of a local medicinal herb (Achyranthes aspera) as dietary supplement to sows to prevent diarrhea in piglets. Livestock Research for Rural Development. Volume 15, Article #55. Retrieved , from http://www.lrrd.org/lrrd15/7/son157.htm