Columbia subject headings:
Harvard subject headings:
Balkan Peninsula--History--20th century--Congresses.
Balkan Peninsula--Politics and government--20th century--Congresses.
Collective memory--Balkan Peninsula--History--Congresses.
Communism--Balkan Peninsula--History--Congresses.
Princeton subject headings:
Balkan Peninsula--History--20th century.
Balkan Peninsula--Politics and government--20th century.
Communism--Balkan Peninsula--History.