Reference

Mikhail A. Akhmetiev, Vladimir N. Benyamovskiy, Nina I. Zaporozhets (2011): E/O biospheric crisis transition "warm" to "cold" biosphere of central part of extratropical Eurasia (stratigraphy, palaeogeography and palaeoclimatology) – Berichte der Geologischen Bundesanstalt – 85: 28.