Columbia subject headings:
Harvard subject headings:
France--Social conditions--19th century.
Germany--Social conditions--19th century.
Labor movement--France
Labor movement--Germany.
Political ballads and songs--France--History and criticism.
Political ballads and songs--France.
Political ballads and songs--Germany--History and criticism.
Political ballads and songs--Germany.
Working class--France--Intellectual life.
Working class--Germany--Intellectual life.
Princeton subject headings:
France--Social conditions--19th century.
Germany--Social conditions--19th century.
Labor movement--France.
Labor movement--Germany.
Political ballads and songs--France.
Political ballads and songs--Germany.