• The Great Ordovician Biodiversification Event: Linked to phytoplankton evolution or to asteroid impacts?Servais, T.; Hints, Olle; Kröger, Björn; Nõlvak, Jaak; Vecoli, M.; Wallin, A.The Seventh Baltic Stratigraphical Conference : 17-18 May 2008, Tallinn, Estonia : abstracts & field guide2008 / p. 63