Columbia subject headings:
Lassalle, Ferdinand, 1825-1864.
Schulze-Delitzsch, Hermann, 1808-1883.
Harvard subject headings:
Labor movement--Austria.
Labor movement--Germany.
Labor movement--Switzerland.
Lassalle, Ferdinand, 1825-1864
Schulze-Delitzsch, Hermann, 1808-1883
Princeton subject headings: