Columbia subject headings:
Soviet Union--History--Revolution, 1917-1921--Participation, German.
Harvard subject headings:
Soviet Union--History--Revolution, 1917-1921--Participation, Foreign.
Soviet Union--History--Revolution, 1917-1921--Participation, German.
World War, 1914-1918--Campaigns--Eastern Front
Princeton subject headings:
Soviet Union--History--Revolution, 1917-1921--Participation, German.