Columbia subject headings:
Harvard subject headings:
Kindergarten--Germany--History--19th century.
Mothers--Employment--Germany--History--19th century.
Nursery schools--Germany--History--19th century.
Working class--Education--Germany--History--19th century.
Princeton subject headings:
Families--Germany--History--19th century.
Mothers--Employment--Germany--History--19th century.
Nursery schools--Germany--History--19th century.
Socialization--Germany--History--19th century.