M. Wagreich, T. Küchler and H. Summesberger (2003) “Correlation of calcareous nannofossil zones to the local first occurrence of Pachydiscus neubergicus (von Hauer, 1858) (Ammonoidea) in European Upper Cretaceous sections”, Netherlands Journal of Geosciences, 82, pp. 283-288. doi: 10.1017/S0016774600020874.