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A.A. Klompmaker and B.J.H.M. van den Berkmortel 2007. Earliest Jurassic (Hettangian) psiloceratoid ammonites from a subrosion pipe at Winterswijk, the eastern Netherlands. Netherlands Journal of Geosciences. 86, (Dec. 2007), 379 - 388. DOI:https://doi.org/10.1017/S0016774600023593.