Columbia subject headings:
Ballads, Spanish--History and criticism.
Heine, Heinrich, 1797-1856--Criticism and interpretation.
Heine, Heinrich, 1797-1856--Knowledge and learning.
Literature.
Harvard subject headings:
Ballads, Spanish--History and criticism.
Heine, Heinrich, 1797-1856--Knowledge--Literature.
Heine, Heinrich, 1797-1856--Versification.
Princeton subject headings:
Ballads, Spanish--History and criticism.
Heine, Heinrich, 1797-1856--Criticism and interpretation.
Heine, Heinrich, 1797-1856--Knowledge--Literature.