Upper Oligocene. (In: Stratigraphy of the Mesozoic and Cenozoic of the Western Siberian Lowlands. V.F.Kozyreva, editor)
Foreign title:
Verkhii Oligotsen. (In-Stratigrafiya Mezozoya i Kainozoya Zapadno-Sibirskoi Nizmennosti. V.F.Kozyreva,editor)
Reference:
Ivanova,E.A. et al. (1957)
Upper Oligocene. (In: Stratigraphy of the Mesozoic and Cenozoic of the Western Siberian Lowlands. V.F.Kozyreva, editor) [ Verkhii Oligotsen. (In-Stratigrafiya Mezozoya i Kainozoya Zapadno-Sibirskoi Nizmennosti. V.F.Kozyreva,editor) ] Gosudarstyy Soyuznyy Zapadno-Sibirskiy Nefterazvedochnyy Trest
P. 133- 135