Graute, Ulrich. “Political Co-Operation and the Joint Decision Trap: Co-Operation Within the Multi-Level System of European Spatial Development Policy”. Raumforschung und Raumordnung | Spatial Research and Planning 62, no. 1 (January 31, 2004): 18–26. Accessed August 15, 2026. https://rur.oekom.de/index.php/rur/article/view/1538.