NIERMANN, Stefan. Convergence of economic structures of german cities. Raumforschung und Raumordnung | Spatial Research and Planning, DE, v. 61, n. 4, p. 252–258, 2003. DOI: 10.1007/BF03182960. Disponível em: https://rur.oekom.de/index.php/rur/article/view/1587. Acesso em: 9 nov. 2026.