Columbia subject headings:
Harvard subject headings:
Arthur, King--Early works to 1800.
Arthur, King.
Celts--Folklore.
Celts--Great Britain--Legends--Early works to 1800.
Great Britain--History--To 449.
Legends--British Isles
Merlin (Legendary character)
Merlin (Legendary character)--Early works to 1800.
Princeton subject headings:
Arthur, King
Great Britain--History--To 449.
Legends, Celtic.
Merlin (Legendary character)