Bolʹšaâ soveckaâ enciklopediâ / Glav. redaktor A. M. Prohorov. - Moskva : Sov. entsiklopediia, 1969-. - 30 v. : ISBN: RussianRef1059 Subjects--Topical Terms: Encyclopedias and dictionaries, Russian. Dewey Class. No.: 039.17 / Bo, 3