O.A. Abbink, J.H.A. Van Konijnenburg-Van Cittert and H. Visscher 2004. A sporomorph ecogroup model for the Northwest European Jurassic - Lower Cretaceousi: concepts and framework. Netherlands Journal of Geosciences. 83, (Mar. 2004), 17-31. DOI:https://doi.org/10.1017/S0016774600020436.