Columbia subject headings:
Harvard subject headings:
Danube River Region--Economic conditions--Congresses.
Danube River Region--Forecasting--Congresses.
Danube River Region--History--Congresses.
Danube River Region--Politics and government--Congresses.
Danube River Region--Social life and customs--Congresses.
Danube River Valley--Congresses.
Europe, Central--Economic conditions--Congresses.
Europe, Central--History--Congresses.
Europe, Central--Politics and government--Congresses.
Europe, Central--Social conditions--Congresses.
Europe, Eastern--Congresses.
European Union--Europe, Central--Congresses.
Social integration--Danube River Region--Congresses.
Princeton subject headings:
Danube River Valley--Congresses.
Europe, Central--Economic conditions--Congresses.
Europe, Central--History--Congresses.
Europe, Central--Politics and government--Congresses.
Europe, Central--Social conditions--Congresses.
Europe, Eastern--Congresses.
European Union--Europe, Central--Congresses.