Columbia subject headings:
Baltic States--Foreign relations--Soviet Union.
Baltic States--Foreign relations--Treaties.
Soviet Union--Foreign relations--Baltic States.
Soviet Union--Foreign relations--Treaties.
Harvard subject headings:
Baltic States--Foreign relations--Soviet Union.
Baltic States--Foreign relations--Treaties.
Soviet Union--Foreign relations--Baltic States.
Soviet Union--Foreign relations--Treaties.
Princeton subject headings:
Baltic States--Foreign relations--Soviet Union.
Baltic States--Foreign relations--Treaties.
Soviet Union--Foreign relations--Baltic States.
Soviet Union--Foreign relations--Treaties.
Treaties.