Columbia subject headings:
Latvia--History--1914-1918.
Latvia--History--1918-1940.
Soviet Union--History--Allied intervention, 1918-1920.
Harvard subject headings:
Latvia--History--1914-1918.
Latvia--History--1918-1940.
Soviet Union--History--Allied intervention, 1918-1920.
Princeton subject headings:
Latvia--History--1914-1918.
Latvia--History--1918-1940.
Soviet Union--History--Allied intervention, 1918-1920.