Columbia subject headings:
Harvard subject headings:
Canals--Belgium.
Canals--Germany
Canals--Netherlands
Infrastructure (Economics)
Rhine-Meuse Delta (Netherlands)
Scheldt River Estuary (Netherlands and Belgium)
Princeton subject headings:
Canals--Belgium.
Canals--Germany.
Canals--Netherlands.
Infrastructure (Economics)
Rhine-Meuse Delta (Netherlands)
Scheldt River Estuary (Netherlands and Belgium)