1. Berggren, W.A. and Van Couvering, J.A., 1974. The late Neogene, biostratigraphy, geochronology, and paleoclimatology of the last 15 million years in marine and continental sequences. Elsevier Publishing Co., Amsterdam, 216 p.
2. Daams, R. and Freudenthal, M., 1981. Aragonian: The stage concept versus Neogene mammal zones. Scripta Geologica, v. 62, p. 1–17.
3. Daams, R., Freudenthal, M., and Weerd, A. Van de, 1977. Aragonian, a new stage for continental deposits of Miocene age. Newsletter Stratigraphy, v. 6, p. 42–55.
4. Fahlbusch, V., 1976. Report on the International Symposium on Mammalian Stratigraphy of the European Tertiary. Newsletter Stratigraphy, v. 5, p. 160–167.
5. Hedberg, H.D. (ed.), 1976. International Stratigraphic Guide. John Wiley and Sons Publishers, New York, 200 p.