Tài liệu tham khảo WikiPedia: Khoai_từ http://vnexpress.net/gl/doi-song/2008/07/3ba04d72 http://www.khuyennongvn.gov.vn/k-ban-co-biet/khoai... http://www.toquoc.gov.vn/Thongtin/Thuoc-Viet/Dung-... https://web.archive.org/web/20100719003113/http://...