Raffi, Isabella; Backman, Jan; Zachos, James C.; Sluijs, Appy (2009): The response of calcareous nannofossil assemblages to the Paleocene Eocene Thermal Maximum at the Walvis Ridge in the South Atlantic. Elsevier, Amsterdam, Netherlands, Marine Micropaleontology, 70 (3-4), 201-212, georefid:2010-044886