Columbia subject headings:
Harvard subject headings:
Agriculture and state--Balkan Peninsula--History--Congresses.
Agriculture--Balkan Peninsula--History.
Agriculture--Europe, Central--History.
Balkan Peninsula--Population.
Ethnicity--Balkan Peninsula--History--Congresses.
Europe, Central--Population.
Land reform--Balkan Peninsula--History--Congresses.
Princeton subject headings:
Agriculture--Balkan Peninsula--History.
Agriculture--Europe, Central--History.
Balkan Peninsula--Population.
Europe, Central--Population.