Khmelnychyi , S., B. Karpenko, and D. Bardash. “PECULIARITIES OF DEVELOPMENT OF UKRAINIAN REPAIR HEIFERS RED-AND-WHITE AND BLACK-AND-WHITE DAIRY BREEDS IN FARMS OF SUMY REGION”. Bulletin of Sumy National Agrarian University. The Series: Livestock, no. 2 (41), Oct. 2020, pp. 18-23, doi:10.32845/bsnau.lvst.2020.2.3.