Philip L. Gibbard, Martin J. Head, Michael J. C. Walker: Formal ratification of the Quaternary System/Period and the Pleistocene Series/Epoch with a base at 2.58 Ma. In: Journal of Quaternary Science. Band25, Nr.2, Februar 2010, S.96–102, doi:10.1002/jqs.1338.
stratigraphy.org
D. Rio u. a.: The Gelasian Stage (Upper Pliocene): A new unit of the global standard chronostratigraphic scale. In: Episodes. 21, 1998, S. 82–87. (online, pdf)