Columbia subject headings:
Saint Petersburg (Russia)--History--20th century.
Harvard subject headings:
Saint Petersburg (Russia)--Economic conditions--20th century.
Saint Petersburg (Russia)--History--20th century.
Saint Petersburg (Russia)--Social conditions--20th century.
Princeton subject headings:
Saint Petersburg (Russia)--Economic conditions--20th century.
Saint Petersburg (Russia)--History--20th century.
Saint Petersburg (Russia)--Social conditions--20th century.