Columbia subject headings:
Bachmann, Ingeborg, 1926-1973--Criticism and interpretation.
Henze, Hans Werner, 1926-2012--Criticism and interpretation.
Libretto.
Harvard subject headings:
Bachmann, Ingeborg, 1926-1973--Criticism and interpretation.
Henze, Hans Werner, 1926-2012--Criticism and interpretation.
Libretto.
Princeton subject headings:
Bachmann, Ingeborg, 1926-1973--Criticism and interpretation.
Librettos.
Operas--Librettos.