Columbia subject headings:
Cistercian monasteries--Europe--History.
Cistercians--Europe--History.
Salt industry and trade--Europe--History.
Salt mines and mining--Europe--History.
Harvard subject headings:
Cistercians--Europe--History.
Monasteries--Europe--History.
Salt industry and trade--Europe--History.
Salt mines and mining--Europe--History.
Princeton subject headings:
Cistercians--Europe--History.
Monasteries--Europe--History.
Salt industry and trade--Europe--History.
Salt mines and mining--Europe--History.