Columbia subject headings:
Harvard subject headings:
Landscape protection--Government policy--Germany--North Rhine-Westphalia.
Nature conservation--Germany--North Rhine-Westphalia.
Nature conservation--Government policy--Germany--North Rhine-Westphalia.
Princeton subject headings:
Landscape protection--Government policy--Germany--North Rhine-Westphalia.
Nature conservation--Germany--North Rhine-Westphalia.
Nature conservation--Government policy--Germany--North Rhine-Westphalia.