Growe, Anna, and Hans H. Blotevogel. “Knowledge Hubs in the German Urban System: Identifying Hubs by Combining Network and Territorial Perspectives”. Raumforschung und Raumordnung | Spatial Research and Planning 69, no. 3 (June 30, 2011): 175–185. Accessed August 15, 2026. https://rur.oekom.de/index.php/rur/article/view/786.