Columbia subject headings:
Operas--Analysis, appreciation.
Wagner, Richard, 1813-1883. Ring des Nibelungen.
Harvard subject headings:
Operas--Analysis, appreciation
Wagner, Richard, 1813-1883. Ring des Nibelungen.
Princeton subject headings:
Wagner, Richard, 1813-1883--Criticism and interpretation.
Wagner, Richard, 1813-1883. Der Ring des Nibelungen.