M. Mahani, I. Jannah, E. Harahap, M. Salman, and N. Habib, “Antihyperglycemic Effect of Propolis Extract from Two Different Provinces in Indonesia”, Int. J. Adv. Sci. Eng. Inf. Technol., vol. 3, no. 4, pp. 264–267, Aug. 2013.