Pepliński, Benedykt, Rafał Baum, and Karol Wajszczuk. 2012. “Changes of the Energy Consumption of Production in Selected Farms in Wielkopolska”. Journal of Agribusiness and Rural Development 26 (4), 69-80. http://www1.up.poznan.pl/jard/index.php/jard/article/view/576.