VON SEHT, Hauke. Regional Planning for the Extraction of Non-energy Raw Materials: an analysis of requirements, Problems and options on the Basis of experiences in north rhine-Westphalia. Raumforschung und Raumordnung | Spatial Research and Planning, DE, v. 68, n. 5, p. 419–431, 2010. DOI: 10.1007/s13147-010-0056-0. Disponível em: https://rur.oekom.de/index.php/rur/article/view/907. Acesso em: 15 aug. 2026.