Raffi, Isabella; De Bernardi, Bianca (2008): Response of calcareous nannofossils to the Paleocene-Eocene thermal maximum; observations on composition, preservation and calcification in sediments from ODP Site 1263 (Walvis Ridge, SW Atlantic). Elsevier, Amsterdam, Netherlands, Marine Micropaleontology, 69 (2), 119-138, georefid:2009-017178