Columbia subject headings:
Labor movement--Austria--History.
Labor movement--Hungary--History.
Socialism--Austria--History.
Socialism--Hungary--History.
Harvard subject headings:
Labor movement--Austria--History--Congresses.
Labor movement--Hungary--History--Congresses.
Princeton subject headings:
Labor movement--Austria--History.
Labor movement--Hungary--History.
Socialism--Austria--History.
Socialism--Hungary--History.