Columbia subject headings:
Harvard subject headings:
Labor leaders--Austria--Biography--Congresses.
Labor leaders--Germany--Biography--Congresses.
Labor movement--Austria--Biography--Congresses.
Labor movement--Germany--Biography--Congresses.
Princeton subject headings:
Labor leaders--Austria--Biography--Congresses.
Labor leaders--Germany (East)--Biography--Congresses.
Labor movement--Austria--Biography--Congresses.