Columbia subject headings:
Celts--Great Britain--History.
Celts--Ireland--History.
Harvard subject headings:
Celts--Great Britain.
Celts--Ireland.
Great Britain--Antiquities, Celtic.
Great Britain--History--To 1066.
Ireland--Antiquities, Celtic.
Ireland--History--To 1172.
Princeton subject headings:
Celts--Great Britain--History.