References:

Applegate, J. L. & Bergen, J. A. (1988). Cretaceous calcareous nannofossil biostratigraphy of sediments recovered from the Galicia Margin, ODP Leg 103. Proceedings of the Ocean Drilling Program. Scientific Results. 103: 293-348. gs

Bown, P. R. (2005c). Early to Mid-Cretaceous Calcareous Nannoplankton from the Northwest Pacific Ocean, Leg 198, Shatsky Rise. Proceedings of the Ocean Drilling Program. Scientific Results. 198: 1-82. gs

Covington, J. M. & Wise, S. W. (1987). Calcareous nannofossil biostratigraphy of a Lower Cretaceous deep-sea fan complex: Deep Sea Drilling Project Leg 93 Site 603, lower continental rise off Cape Hatteras. Initial Reports of the Deep Sea Drilling Project. 93: 617-660. gs

Thierstein, H. R. (1971). Tentative Lower Cretaceous Calcareous Nannoplankton Zonation. Eclogae Geologicae Helvetiae. 64: 459-488. gs