Sondermann, Martin. “Planning Culture As a System of Meaning. A Study Using the Example of Cooperative Green Urban Development in Düsseldorf, Germany”. Raumforschung und Raumordnung | Spatial Research and Planning 75, no. 1 (February 28, 2017): 45–56. Accessed August 15, 2026. https://rur.oekom.de/index.php/rur/article/view/479.