A.H, Zaibunnisa, Siti Rohani K, Noor Adillah A, Shahiza M, and Noorlaila A. 2005. “Effect of Ascorbic Acid, Alpha-Tocopherol, Beta-Carotene and Total Polyphenol on Antioxidant Activity in Selected Malaysian Edible Plants”. Malaysian Journal of Science 24 (1):219-24. https://juku.um.edu.my/index.php/MJS/article/view/8981.