Wilker, Jost, and Dietwald Gruehn. “The Potential of Contingent Valuation for Planning Practice. The Example of Dortmund Westpark”. Raumforschung und Raumordnung | Spatial Research and Planning 75, no. 2 (April 30, 2017): 171–185. Accessed April 17, 2025. https://rur.oekom.de/index.php/rur/article/view/467.