R. D. Pertiwi, Suwaldi, R. Martien, and E. P. Setyowati, “Radical Scavenging Activity and Quercetin Content of Muntingia calabura L. Leaves Extracted by Various Ethanol Concentration”, J. Food Pharm. Sci, vol. 8, no. 1, pp. 173-183, Feb. 2020.