Verbelchuk , T., Verbelchuk , S., Kovalchuk , I., Kovalchuk , I., Vasiliev , R., & Klim , V. (2021). Balance of ferum and copper in the organs of pigs when using non-traditional natural additives. Bulletin of Sumy National Agrarian University. The Series: Livestock, (2 (45), 77-82. https://doi.org/10.32845/bsnau.lvst.2021.2.11