1. ARE – Swiss Federal Office for Spatial Development (2017): Five Years Territorial Concept Switzerland. Location Decision and Need for Action. Report of 16 January 2017: Berne.
2. BFS – Swiss Federal Statistical Office (2020): Statistics on Swiss Towns 2020: A Look beyond the Core City Limits. Press release of 12 May 2020: Neuchâtel.
3. ESPON – European Spatial Planning Observation Network (2018): SPIMA – Spatial Dynamics and Strategic Planning in Metropolitan Areas. Final Report of 5 March 2018: Luxembourg.
4. Federal Council (1999): Report on the Core Cities.
5. Report of 7 June 1999.