Obruchev V. A. Essays on the geology of Siberia: a geological sketch of the Baykal and Lena regions. In Russian (ask us if in doubt)/Obruchev V. A. Ocherki po geologii Sibiri: Geologicheskiy ocherk Pribaykalya i Lenskogo rayona. Series: Proceedings of the Council for the Study of Productive Forces and the Geological Institute of the Academy of Sciences of the USSR: Publishing House of the Academy of Sciences of the USSR 1932, 4, 128 p. SKUalbbb11b8f1b0cfd60b.