“Antioxidant Activity Test of Effervescent Granules Morinda citrifolia L Leaf Extract with DPPH Free Radical Absorption Method”, J. Trop. Pharm. Chem, vol. 5, no. 4, pp. 365–368, Dec. 2021, doi: 10.30872/j.trop.pharm.chem.v5i4.260.