Reference

John H. Callomon, Gerd Dietl, Hans-Jörg Niederhöfer (1992): On the true stratigraphic posItion of Macrocephalites macrocephalus (Schlotheim, 1813) and the nomenclature of the Standard Middle Jurassic "Macrocephalus Zone" – Stuttgarter Beiträge Naturkunde Serie B [Paläontologie] – 185_B: 1 - 65.