D. P. M. Yusuf, A. T. Kawareng, and N. Indriyanti, “Skrining Fitokimia dan Uji Aktivitas Antioksidan Ekstrak Etanol Propolis Lebah Kelulut (Heterotrigona itama): Phytochemical Screening and Antioxidant Activity Test of Kelulut Bee Propolis (Heterotrigona itama) Ethanol Extract”, Proc. Mul. Pharm. Conf., vol. 14, no. 1, pp. 237–241, Dec. 2021.