Kochuk-Yashchenko , O., Kucher , D., Shapran , I. and Mosiichuk , M. (2020) “The efficiency of index selection in herd of the Simental breed for organic milk production”, Bulletin of Sumy National Agrarian University. The series: Livestock, (2 (41), pp. 47-55. doi: 10.32845/bsnau.lvst.2020.2.8.