R.T. van Balen and F.S. Busschers (2010) “Human presence in the central Netherlands during early MIS 6 (~170-190 Ka): evidence from early Middle Palaeolithic artefacts in ice-pushed Rhine-Meuse sediments”, Netherlands Journal of Geosciences, 89, pp. 77 - 83. doi: 10.1017/S0016774600000834.