Columbia subject headings:
Comparative civilization.
Forecasting.
History, Modern.
History--Methodology.
Russia--History.
Soviet Union--History.
Harvard subject headings:
Comparative civilization
Forecasting
History, Modern
History--Methodology
Russia--History.
Soviet Union--History.
Princeton subject headings:
Cycles.
Russia--History--Philosophy.
Soviet Union--History--Philosophy.
World history--Philosophy.