Sri Wahdaningsih, Sugeng Riyanto and Retno Murwanti 2017. The radical scavenging activity of 2-2’ diphenyl -1- picrylhydrazil (DPPH) on the methanol extracts and Ethyl acetate fractions of red dragon fruit peel (Hylocereus polyrhizus (F.A.C.Weber) Britton dan Rose). International Journal of Phytomedicine. 9, 1 (Mar. 2017), 79–82.