Seow-Mun Hue and  Amru Nasrulhaq Boyce and  Chandran Somasundram,  Comparative Study on the Antioxidant Activity of Leaf Extract and Carotenoids Extract from Ipomoea batatas var. Oren (Sweetpotato) Leaves.   journal   = {International Journal of Nutrition and Food Engineering}, [online]. World Academy of Science, Engineering and Technology.
    October 2011, vol. 58(10). 604 - 607
    [viewed 29 January 2022]. Available from: https://publications.waset.org/pdf/10688.