1. Andrawis, S. F., & Abdel Malik, W. M. (1981). Lower/middle Miocene boundary in the Gulf of Suez region, Egypt. Newsletters on Stratigraphy,
10, 156–163.
2. Berggren, W. A., Swisher, C. C., & Aubry, M. P. (1995). A revised Cenozoic geochronology and chronostratigraphy. In: Geochronology time scales and global stratigraphic correlation. Society of Sedimentary Geology,
54, 277–302.
3. Bizon, G., & Bizon, J. J. (1972). Atlas des principaux foraminiferes planctoniques du basin méditerranéen. Oligocéne á Quaternaire. Paris: Editions Technip.
4. Blow, W. H. (1969). Late middle eocene to recent planktonic foraminiferal biostratigraphy. In P. Bronnimann, & H. H Renz (Eds), Proceedings of the first international conference on planktonic microfossils (Geneva, 1967), vol. 1 (pp. 199–421). Leiden, E. H., Brill.
5. Bolli, H. M. (1957). Planktonic foraminifera from the Oligocene-Miocene Cipero and Lengua formations of Trinidad, B.W.I. In A. R. Loeblich, H. Tappan, J. P. Beckmann, H. M. Bolli, E. M. Gallitelli, & J. C. Troelsen (Eds.), Studies in Foraminifery, Bulletin of the U.S. National Museum (pp. 97–123). Vol. 215.