Obruchev V. A. History of geological research in Siberia. Book 1, 2, 3, 4, 5. In Russian (ask us if in doubt)/Obruchev V. A. Istoriya geologicheskogo issledovaniya Sibiri. Kniga 1, 2, 3, 4, 5. Book 2: Period 2 (1801-1850) (Helmersen, Hoffman, Middendorf, Chikhachev, Shurovsky, Erman). Book 3: Period 3 (1851-1888) (Krapotkin, Maak, Meglitsky, Chekanovsky, Chersky, Schmidt). Book 4: Period 4 (1889-1917). SKUalb888aa2d92c173ad7.