Columbia subject headings:
Harvard subject headings:
Britons--Sources.
Celts--Great Britain--History--Sources.
Celts--Great Britain--History--To 1500--Sources.
Great Britain--Antiquities, Celtic--Sources.
Great Britain--Civilization--To 1066--Sources.
Princeton subject headings:
Civilization, Celtic--Sources.
Great Britain--Civilization--To 1066--Sources.