Columbia subject headings:
Europe--Economic integration--Congresses.
Inland water transportation--Europe--Congresses.
Transportation--Europe--Congresses.
Harvard subject headings:
Europe--Economic integration--Congresses.
Infrastructure (Economics)--Europe.
Inland water transportation--Europe--Congresses.
Transportation--Europe
Transportation--Europe--Congresses
Princeton subject headings:
Europe--Economic integration--Congresses.
Inland water transportation--Europe--Congresses.
Transportation--Europe--Congresses.