Reference
Istvan Fözy, Attila Fogarasi, Nico M.M. Janssen (2008): Early Cretaceous Cephalopod and Calcareous Nannofossil Biostratigraphy of the Bersek Quarry (Gerecse Mts, Transdanubian Range, Hungary) – Berichte der Geologischen Bundesanstalt – 74: 41 - 42.