Palaeogeography, Palaeoclimatology, Palaeoecology, 536:109395, 1-16. Elsevier van der Boon, A, van der Ploeg, R, Cramwinckel, M J, Kuiper, K F, Popov, S V, Tabachnikova, I P, Palcu, D V & Krijgsman, W 2019, ' Integrated stratigraphy of the Eocene-Oligocene deposits of the northern Caucasus (Belaya River, Russia) : Intermittent oxygen-depleted episodes in the Peri-Tethys and Paratethys ', Palaeogeography, Palaeoclimatology, Palaeoecology, vol. 536, 109395, pp. 1-16 . https://doi.org/10.1016/j.palaeo.2019.109395 Palaeogeography, Palaeoclimatology, Palaeoecology, 536. Elsevier Saunders