Gabi, Simone, and Alain Thierstein. “A «Regionalpark” As a Field of Action for Metropolitan Governance: A Case Study in the Zurich Glattal-Stadt”. Raumforschung Und Raumordnung | Spatial Research and Planning, vol. 63, no. 1, Jan. 2005, pp. 21–31, https://doi.org/10.1007/BF03183453.