Meijer , Tom, Ronald Pouwer, Piet Cleveringa, Hein de Wolf, Freek S. Busschers, and Frank P. Wesselingh. “Fossil Molluscs from Borehole Hollum (Ameland, the Netherlands) Constrain Three Successive Quaternary Interglacial Marine Intervals in the Southern North Sea Basin”. Netherlands Journal of Geosciences 100 (May 7, 2021). Accessed March 26, 2026. https://njgjournal.nl/index.php/njg/article/view/11610.