Spychała, Marcin. “Key Economic Growth Factors in Poland and Selected Countries of the World During the Years 2005-2013”. Studia Oeconomica Posnaniensia 3, no. 4 (April 30, 2015): s. 5–29. Accessed September 3, 2026. https://journals.ue.poznan.pl/soep/article/view/3929.