Sklyarenko, Y., O. Metlitska, V. Ladyka, and I. Ivankova. 2018. “Lebedyn Cattle Breed Genetic Pool Genesis and New Types and Breeds Developed on Its Base”. Bulgarian Journal of Agricultural Science 24 (6): 1114–1122. https://agriacad.eu/ojs/index.php/bjas/article/view/5013.