W.E. Westerhoff, H.A. Kemna, and W. Boenigk. 2008. “The Confluence Area of Rhine, Meuse, and Belgian Rivers: Late Pliocene and Early Pleistocene Fluvial History of the Northern Lower Rhine Embayment”. Netherlands Journal of Geosciences 87 (March):107 -25. https://doi.org/10.1017/S0016774600024070.