CIEŚLIK, Andrzej; MICHAŁEK, Jan Jakub; MYCIELSKI, Jerzy. Social Development and International Trade in Central Europe. Equilibrium. Quarterly Journal of Economics and Economic Policy, Olsztyn, v. 7, n. 2, p. 7–19, 2012. DOI: 10.12775/EQUIL.2012.008. Disponível em: https://economic-policy.pl/index.php/eq/article/view/377. Acesso em: 15 jan. 2026.