David, Carl-Heinz. 2005. “On the Convergence of the National Spatial Planning Policies of France and Germany in the Post-EUREK Process: The Principle of Subsidiarity in the Debate on the European Constitutional Treaty and Its Impacts on the Formation of a Common Spatial Development Policy”. Raumforschung Und Raumordnung | Spatial Research and Planning 63 (1): 11–20. https://doi.org/10.1007/BF03183452.