Columbia subject headings:
Harvard subject headings:
Düsseldorfer Malerschule--Exhibitions.
Painting, German--Germany--Düsseldorf--19th century--Exhibitions.
Painting, German--Germany--Düsseldorf--20th century--Exhibitions.
Volmer, Horst--Art collections--Exhibitions.
Princeton subject headings:
Düsseldorfer Malerschule--Exhibitions.
Landscape painting--Germany--Wuppertal--Exhibitions.
Painting, Modern--Private collections--Germany--Wuppertal--Exhibitions.
Volmer, Horst--Art collections--Exhibitions.