Collinson, Margaret E.; Barke, Judith; van der Burgh, Johan; van Konijnenburg-van Cittert, Johanna H. A.; Pearce, Martin A.; Bujak, Jonathan; Brinkhuis, Henk (2011): The Eocene Arctic Azolla phenomenon; species composition, temporal range and geographic extent. Geologische Bundesanstalt, Vienna, Austria, In: Egger, Hans (editor), Climate and biota of the early Paleogene; conference program and abstracts, 85, 56, georefid:2012-009421