Reference

Volker Dietze, John H. Callomon, Günter Schweigert, Robert B. Chandler (2005): The ammonite fauna and biostratigraphy of the Lower Bajocian (Ovale and Laeviuscula zones) of E Swabia (S Germany) – Stuttgarter Beiträge Naturkunde Serie B [Paläontologie] – 353_B: 1 - 82.