W.J. Autin. “Stratigraphic Analysis and Paleoenvironmental Implications of the Wijchen Member in the Lower Rhine-Meuse Valley of the Netherlands”. Netherlands Journal of Geosciences 87 (December 1, 2008): 291 - 307. Accessed February 22, 2025. https://njgjournal.nl/index.php/njg/article/view/11905.