Sedlák, É., L. Borsodi, E. Boldizsár, É. Preininger, M. László, É. Szőke, and I. Gyurján. “Bioactive Phenols in Leaves of Forsythia Species”. International Journal of Horticultural Science 14, no. 3 (May 19, 2008): 57–59. Accessed April 10, 2021. https://ojs.lib.unideb.hu/IJHS/article/view/804.