Columbia subject headings:
Harvard subject headings:
Balkan Peninsula--History.
Byzantine Empire--Foreign relations--Serbia.
Dušan, Emperor of Serbia, approximately 1308-1355.
Serbia--Foreign relations--Byzantine Empire.
Serbia--History--To 1456.
Princeton subject headings:
Balkan Peninsula--History.
Byzantine Empire--Foreign relations--Yugoslavia--Serbia.
Dušan, Emperor of Serbia, approximately 1308-1355.
Serbia--Foreign relations--Byzantine Empire.
Serbia--History--To 1456.