BONGARTZ, Michael. Precautionary flood protection as an element of regional planning in North Rhine-Westphalia. Raumforschung und Raumordnung | Spatial Research and Planning, DE, v. 61, n. 5, p. 379–394, 2003. DOI: 10.1007/BF03183881. Disponível em: https://rur.oekom.de/index.php/rur/article/view/1581. Acesso em: 29 sep. 2026.