Columbia subject headings:
Harvard subject headings:
Estonia--History--1918-1940--Congresses.
Ethnic conflict--Estonia--History--20th century--Congresses.
Ethnic conflict--Latvia--History--20th century--Congresses.
Latvia--History--1918-1940--Congresses.
Minorities--Estonia--History--20th century--Congresses.
Minorities--Latvia--History--20th century--Congresses.
Princeton subject headings:
Estonia--Ethnic relations--Congresses.
Germans--Baltic States--Congresses.
Latvia--Ethnic relations--Congresses.
Minorities--Estonia--Congresses.
Minorities--Latvia--Congresses.