Columbia subject headings:
Grail.
Robert, de Boron, active 13th century.
Harvard subject headings:
Arthurian romances--History and criticism.
Grail
Grail--Legends--History and criticism
Lancelot (Legendary character)--Romances--History and criticism.
Robert de Boron, active 13th century. Roman de l'estoire dou Graal.
Robert, de Boron, active 13th century.
Princeton subject headings:
Grail.
Robert, de Boron, active 13th century.