Columbia subject headings:
Charlemagne, Emperor, 742-814--Romances--Concordances.
Epic literature, Latin (Medieval and modern)--Concordances.
Karolus Magnus et Leo Papa--Concordances.
Leo III, Pope, -816--In literature.
Harvard subject headings:
Karolus Magnus et Leo Papa--Concordances.
Princeton subject headings:
Karolus Magnus et Leo Papa--Concordances.