Columbia subject headings:
Harvard subject headings:
Soviet Union--History--Revolution, 1917-1921--Congresses.
Soviet Union--History--Revolution, 1917-1921--Historiography--Congresses.
Soviet Union--History--Revolution, 1917-1921--Literature and the revolution--Congresses.
Soviet Union--History--Revolution, 1917-1921--Social aspects--Congresses.
Princeton subject headings:
Russia--History--February Revolution, 1917--Congresses.
Soviet Union--History--Revolution, 1917-1921--Congresses.