KUC, M. The use of taxonomy methods for clustering European Union countries due to the standard of living. Oeconomia Copernicana, [S. l.], v. 3, n. 2, p. 5–24, 2012. DOI: 10.12775/OeC.2012.006. Disponível em: http://economic-research.pl/Journals/index.php/oc/article/view/465. Acesso em: 27 jan. 2022.