Wąs, Adam, Katarzyna Zawalińska, and Wolfgang Britz. 2014. “Impact of "Grening" the Common Agricultural Policy on Sustainability of European Agriculture: From Perspective of the Baltic Sea Countries”. Journal of Agribusiness and Rural Development 34 (4), 191-212. http://www1.up.poznan.pl/jard/index.php/jard/article/view/494.