Columbia subject headings:
Balkan Peninsula--Emigration and immigration--20th century.
Political refugees--Legal status, laws, etc.--Balkan Peninsula.
Russians--Balkan Peninsula--History--20th century.
Russians--Legal status, laws, etc.--Balkan Peninsula--20th century.
Soviet Union--Emigration and immigration.
Harvard subject headings:
Balkan Peninsula--Emigration and immigration--20th century.
Political refugees--Legal status, laws, etc.--Balkan Peninsula.
Russians--Balkan Peninsula--History--20th century.
Russians--Legal status, laws, etc.--Balkan Peninsula--20th century.
Soviet Union--Emigration and immigration.
Princeton subject headings: