Columbia subject headings:
Balkan Peninsula--History, Military.
Balkan Peninsula--Politics and government--19th century.
Balkan Peninsula--Politics and government--20th century.
Balkan Peninsula--Politics and government--21st century.
Harvard subject headings:
Balkan Peninsula--History, Military.
Balkan Peninsula--Politics and government--19th century.
Balkan Peninsula--Politics and government--20th century.
Balkan Peninsula--Politics and government--21st century.
Princeton subject headings:
Balkan Peninsula--History, Military.
Balkan Peninsula--Politics and government--19th century.
Balkan Peninsula--Politics and government--20th century.
Balkan Peninsula--Politics and government--21st century.