Schumacher, Stefanie; Lazarus, David (2004): Regional differences in pelagic productivity in the late Eocene to early Oligocene; a comparison of southern high latitudes and lower latitudes. Elsevier, Amsterdam, Netherlands, In: Kiessling, Wolfgang (editor), Lazarus, David (editor), Mesozoic-Cenozoic bioevents, 214 (3), 243-263, georefid:2005-004716