Geogenostic description of the Lower Silurian and Devonian systems of the St. Petersburg province

Geogery description of the Lower Silurian and Devonian systems of the St. Petersburg province / Bok, Ivan Ivanovich (1844-1916).- St. Petersburg.: type.Imp.Acad.sciences, 1868. -605: Territory..Source of an electronic copy: Russian Geographical Society