Hofker 1966. Maestrichtian, Danian and Paleocene Foraminifera. The Foraminifera of the type-Maestrichtian in South Limburg, Netherlands, together with the Foraminifera of the underlying Gulpen Chalk and the overlying calcareous sediments; the Foraminifera of the Danske Kalk and the overlying greensands and clays as found in Denmark. Palaeontographica Suppl, 10 1966: 1-376