David, C.-H. (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