Columbia subject headings:
Ballads--Congresses.
Poetry, Medieval--Congresses.
Harvard subject headings:
Ballads--Europe--Congresses.
Ballads--Europe--History and criticism--Congresses.
Poetry, Medieval--Congresses.
Poetry, Medieval--History and criticism--Congresses.
Princeton subject headings:
Ballads, European--Congresses.
Poetry, Medieval--Congresses.