Ivanov , Ihor, Yuliia Markhaichuk, and Olena Shcherbyna. “Generational Recurrence of the Breeding Value of Breeding Bulls of the Holstein Breed of German Selection.”. Bulletin of Sumy National Agrarian University. The series: Livestock, no. 2 (45) (May 31, 2021): 83-87. Accessed October 26, 2021. https://snaubulletin.com.ua/index.php/ls/article/view/318.