Mühl, Gerald. “What Contribution Can Regional Planning Capable Make to the Implementation of a „Sustainable” Approach to Securing the Supply of Raw Materials? The Example of Sand and Gravel”. Raumforschung und Raumordnung | Spatial Research and Planning 57, no. 4 (July 31, 1999): 273–283. Accessed August 15, 2026. https://rur.oekom.de/index.php/rur/article/view/1097.