Columbia subject headings:
Arthurian romances--History and criticism.
Chivalry in literature.
Grail--Romances--History and criticism.
Queste del Saint Graal.
Harvard subject headings:
Grail--Legends--History and criticism
Queste del Saint Graal.
Princeton subject headings:
Grail--Legends--History and criticism.
Queste del Saint Graal.