P. Cleveringa, T. Meijer, R.J.W. van Leeuwen, H. de Wolf, R. Pouwer, T. Lissenberg, and A.W. Burger. 2000. “The Eemian Stratotype Locality at Amersfoort in the Central Netherlands: A Re-Evaluation of Old and New Data”. Netherlands Journal of Geosciences 79 (August):197 - 216. https://doi.org/10.1017/S0016774600023659.