Columbia subject headings:
Church music--Catholic Church.
Church music--Portugal--500-1400.
Church music--Spain--500-1400.
Hymns, Latin (Medieval and modern)--Portugal--History and criticism.
Hymns, Latin (Medieval and modern)--Spain--History and criticism.
Harvard subject headings:
Church music--Catholic Church
Church music--Portugal--500-1400.
Church music--Spain--500-1400.
Hymns, Latin (Medieval and modern)--Portugal--History and criticism.
Hymns, Latin (Medieval and modern)--Spain--History and criticism.
Princeton subject headings:
Church music--Catholic Church.
Church music--Portugal--500-1400.
Church music--Spain--500-1400.
Hymns, Latin (Medieval and modern)--Portugal--History and criticism.
Hymns, Latin (Medieval and modern)--Spain--History and criticism.