Columbia subject headings:
Drawing, European--Exhibitions.
Houben, Wilhelm, 1910-1991--Art collections--Exhibitions.
Painting, European--Exhibitions.
Harvard subject headings:
Princeton subject headings:
Drawing, Italian--Exhibitions.
Houben, Wilhelm, 1910-1991--Art collections--Exhibitions.
Painting, European--Exhibitions.
Painting, Italian--Exhibitions.
Wilhelm-Lehmbruck-Museum der Stadt Duisburg--Exhibitions.