Kusumanti, Y., E. M. Ilmawati, and U. F. H. Hasibuan. “2 DIiphenyl 1-1 Pickrylhydrzyl) Method”. Journal of Pharmaceutical and Sciences, vol. 6, no. 4, Nov. 2023, pp. 1658-64, doi:10.36490/journal-jps.com.v6i4.290.