KÜHN DIPL. ING., Manfred; MILSTREY, Ulrike. Medium-Sized Cities as Peripheral Centers: Cooperation, Competition and Hierarchy in Shrinking Regions. Raumforschung und Raumordnung | Spatial Research and Planning, DE, v. 73, n. 3, p. 185–202, 2015. DOI: 10.1007/s13147-015-0343-x. Disponível em: https://rur.oekom.de/index.php/rur/article/view/581. Acesso em: 15 aug. 2026.