Ptasińska-Marcinkiewicz, Joanna. “Sheep Breeding and the Production of Sheep’s Milk in Poland and the World”. Krakow Review of Economics and Management Zeszyty Naukowe Uniwersytetu Ekonomicznego W Krakowie, no. 3(927), Nov. 2015, pp. 43-55, https://doi.org/10.15678/ZNUEK.2014.0927.0304.