Ovechkina, M. N., Kopaevich, L. F., Vishnevskaya, V. S., & Mostovski, M. B. (2021). Upper Cretaceous calcareous nannofossil biostratigraphy of the East European Platform: A proposed regional nannofossil zonation scheme and correlation with foraminifera and radiolarian zones. In M. Montenari (Ed.), Stratigraphy & Timescales (293-437). Elsevier. https://doi.org/10.1016/bs.sats.2021.09.004