J. J. de Vries, and E. van Rees Vellinga. “Buried Channel Aquifers and Present Open Drainage System of East Gelderland, the Netherlands”. Netherlands Journal of Geosciences (January 1, 1972): 45-52. Accessed May 8, 2026. https://njgjournal.nl/index.php/njg/article/view/14517.