N. Hudz, N. Nikolaieva, C. Konyk, I. Kaplun, J. Šimková, and O. Grygorieva, “Methods of Determination of Sum of Flavonoids in Herbal Products by Spectrophotometric Methods”, – 1 –Agrobiodivers Improv Nutr Health Life Qua, no. 1, Nov. 2017.