Khalak, V., and B. Gutyj. “Signs of Reproductive Qualities of Sows of Different Types of Adaptation, Their Variability and Correlation”. Scientific Messenger of LNU of Veterinary Medicine and Biotechnologies. Series: Agricultural Sciences, Vol. 22, no. 92, May 2020, pp. 35-41, doi:10.32718/nvlvet-a9207.