Szmidt, K., A. Kasztelan, M. Kierepka, and A. Samborski. “DIVERSIFICATION IN THE INCOME LEVELS OF EU FARM HOLDINGS SPECIALIZING IN THE PRODUCTION OF MILK”. Acta Scientiarum Polonorum. Oeconomia, Vol. 15, no. 1, Mar. 2016, pp. 133-4, https://js.wne.sggw.pl/index.php/aspe/article/view/4218.