Columbia subject headings:
Heine, Heinrich, 1797-1856--Congresses.
Schumann, Robert, 1810-1856--Congresses.
Harvard subject headings:
Heine, Heinrich, 1797-1856--Congresses.
Schumann, Robert, 1810-1856--Congresses.
Princeton subject headings:
Heine, Heinrich, 1797-1856--Congresses.
Schumann, Robert, 1810-1856--Congresses.