Columbia subject headings:
Soviet Union--History--Congresses.
World War, 1914-1918--Soviet Union--Congresses.
Harvard subject headings:
Soviet Union--History--Congresses.
World War, 1914-1918--Russia--Congresses.
Princeton subject headings:
Soviet Union--History--20th century--Congresses.
World War, 1914-1918--Soviet Union--Congresses.