Poulsen, Niels E., and James B. Riding. “The Jurassic Dinoflagellate Cyst Zonation of Subboreal Northwest Europe: With an Appendix by Bjørn Buchardt: Oxygen Isotope Palaeotemperatures from the Jurassic in Northwest Europe”. GEUS Bulletin 1 (October 28, 2003): 115–144. Accessed October 3, 2022. https://geusbulletin.org/index.php/geusb/article/view/4650.