Węglarzy, Karol, and Małgorzata Bereza. “Diversification of Farm Production to Improve Profitability”. Journal of Agribusiness and Rural Development 24, no. 2 (December 31, 2012): 253-262. Accessed April 30, 2024. http://www1.up.poznan.pl/jard/index.php/jard/article/view/537.