Columbia subject headings:
Harvard subject headings:
Environmental protection--Germany--History.
Eugenics--Germany--History
National socialism and science.
Nature conservation--Germany--History--20th century.
Racism--Germany--History--20th century
Princeton subject headings:
Environmental policy--Germany--History--20th century.
Landscape protection--Social aspects--Germany--History--20th century.
National socialism and science.
Nature conservation--Germany--History--20th century.