Columbia subject headings:
Gregorian chants.
Music--France--Paris--500-1400.
Organa--500-1400--Scores.
Harvard subject headings:
Gregorian chants.
Music--France--Paris--500-1400.
Notre-Dame de Paris (Cathedral)--Songs and music.
Organa--Scores.
Princeton subject headings:
Clausulas (Part songs)
Gregorian chants.
Notre-Dame de Paris (Cathedral)
Organa.
Part songs.
Sacred vocal music--France--Paris--500-1400.