H. D. Salusu, F. Aryani, E. Budiarso, I. W. Kusuma, E. T. Arung, and A. R. Zarta, “Antioxidant Assay of the Ethanolic Extract of Three Species of Rattan Fruits using DPPH Method”, J. Trop. Pharm. Chem., vol. 4, no. 4, pp. 154–162, Dec. 2018.