Jørgensen, Flemming, and Peter B.E. Sandersen. “Mapping of Buried Tunnel Valleys in Denmark: New Perspectives for the Interpretation of the Quaternary Succession”. GEUS Bulletin 15 (July 10, 2008): 33–36. Accessed December 9, 2021. https://geusbulletin.org/index.php/geusb/article/view/5037.