Kisiel, Roman, Renata Marks-Bielewska, and Anna Kowalska. 2011. “Direct Subsidies and Changes in Farms on the Example of Selected Districts of Warmińsko-Mazurskie Voivodship”. Journal of Agribusiness and Rural Development 22 (4), 101-14. http://www1.up.poznan.pl/jard/index.php/jard/article/view/751.