Columbia subject headings:
Baltic States--Foreign relations--Soviet Union--Sources.
Baltic States--History--20th century--Sources.
Soviet Union--Foreign relations--Baltic States--Sources.
Harvard subject headings:
Baltic States--Foreign relations--Soviet Union--Sources.
Baltic States--History--1940-1991--Sources.
Baltic States--History--1991---Sources.
Baltic States--History--Autonomy and independence movements--Sources.
Soviet Union--Foreign relations--Baltic States--Sources.
Princeton subject headings: