BAUMHEIER, Ralph. Co-operative planning of settlements and open spaces in the ‘Regio Unterweser’: A new approach to cross-border co-operation in the area Bremen Lower Saxony. Raumforschung und Raumordnung | Spatial Research and Planning, DE, v. 58, n. 4, p. 337–342, 2000. DOI: 10.1007/BF03183799. Disponível em: https://rur.oekom.de/index.php/rur/article/view/1161.. Acesso em: 22 apr. 2025.