Columbia subject headings:
Socialism--Netherlands--History--1849-
Welcker, J. M.
Working class--Netherlands--History--1849-
Harvard subject headings:
Labor movement--Netherlands--History.
Socialism--Netherlands
Socialism--Netherlands--History.
Welcker, J. M.
Working class--Netherlands--History.
Princeton subject headings:
Labor movement--Netherlands--History.
Socialism--Netherlands--History.
Welcker, J. M.