Columbia subject headings:
Harvard subject headings:
Allier River Region (France)--Social conditions--Congresses.
Loire River (France)--Navigation--Congresses.
Loire River Watershed (France)--Congresses.
Princeton subject headings:
Allier River Region (France)--Social conditions--Congresses.
Loire River (France)--Navigation--Congresses.
Loire River Watershed (France)--Congresses.