Essays on the geology of the Donetsk basin, the Urals, the Caucasus

Yakovlev, N.N.Essays on the geology of the Donetsk basin, the Urals, the Caucasus: from 2 cards.and 4 Fig.In the text / N.N.Yakovlev, prof.Mountains.Institute.-Petrograd: Bookless M. and S. Sabashnikov, 1920. -45 p., 1 l.kart.: Il.;17.5 x 13 cm. -Bibliogr.in the text.- Ex.: Without region..1. Territory (collection).Electronic copy source: PBOriginal storage: St. Petersburg State University