Reference

Norbert Micklich, Ludwig H. Hildebrandt (2010): Emergency excavation in the Grube Unterfeld (Frauenweiler) clay pit (Oligocene, Rupelian; Baden-Württemberg, S Germany): New records and palaeoenvironmental information – Kaupia - Darmstädter Beiträge zur Naturgeschichte – 17: 3 - 21.