Columbia subject headings:
Latvia--History--1914-1918.
Soviet Union--History--Revolution, 1917-1921--Participation, Latvian.
Harvard subject headings:
Soviet Union--History--Revolution, 1917-1921--Participation, Latvian.
Princeton subject headings:
Latvia--History--1914-1918.
Soviet Union--History--Revolution, 1917-1921--Participation, Latvian.