G.F.W. Herngreen 2003. Maastrichtian or Maestrichtian? A proposal to the Subcommission on Cretaceous Stratigraphy (IUGS, International Commission on Stratigraphy). Netherlands Journal of Geosciences. 82, (Aug. 2003), 309-312. DOI:https://doi.org/10.1017/S0016774600020904.