N. Maulidha, A. Fridayanti, and M. A. Masruhim, “Uji Aktivitas Antioksidan Ekstrak Daun Sirih Hitam (Piper sp.) terhadap DPPH (1,1-diphenyl-2-picryl hydrazyl)”, J. Sains Kes., vol. 1, no. 1, pp. 16–20, Mar. 2015.