Columbia subject headings:
Harvard subject headings:
Balkan Peninsula--History--19th century--Congresses.
Eastern question (Balkan)--Congresses.
Serbia--History--Milan Obrenović, 1868-1889--Congresses.
Princeton subject headings:
Balkan Peninsula--History--19th century--Congresses.
Eastern question (Balkan)--Congresses.
Serbia--History--Milan Obrenović, 1868-1889--Congresses.