Columbia subject headings:
French language--To 1300--Versification.
Refrain.
Songs, French--History and criticism.
Trouvères.
Harvard subject headings:
French language--To 1300--Versification
Refrain
Songs, French--History and criticism
Trouvères
Princeton subject headings:
French language--to 1300--Verification.
Music--500-1400--History and criticism.
Refrain.
Songs, French--History and criticism.
Troubadours.
Trouvères.