H.S.M. Jansen, J. Huizer, J.W.A. Dijkmans, & J.E. van Hinte. (2004). Strontium (87Sr/86Sr) dating of marine shells from Pliocene and Pleistocene shallow marine deposits in The Netherlands. Netherlands Journal of Geosciences, 83, 41-48. https://doi.org/10.1017/S001677460002045X