Miłek, Dorota, and Paulina Nowak. “Regional Specialisation As an Endogenous Factor in the Development of Poland?S Provinces”. Equilibrium. Quarterly Journal of Economics and Economic Policy 10, no. 2 (June 30, 2015): 115–135. Accessed May 31, 2023. http://economic-research.pl/Journals/index.php/eq/article/view/221.