S. A. F. Kusuma, A. Tjitraresmi, and G. Susanti, “ANTIBACTERIAL EFFECT OF RED PIPER BETEL LEAF (PIPER CROCATUM RUIZ & PAV.) ETHANOL EXTRACTS TO LACTOBACILLUS ACIDOPHILUS AND L. BIFIDUS GROWTH INHIBITION”, Asian J Pharm Clin Res, vol. 10, no. 14, pp. 65–68, May 2017.