Columbia subject headings:
Art, Modern--20th century--Exhibitions.
Art--Private collections--Germany--Exhibitions.
Artists' books--Germany--Exhibitions.
Private libraries--Germany--Exhibitions.
Speck, Reiner--Art collections--Exhibitions.
Speck, Reiner--Library--Exhibitions.
Harvard subject headings:
Art, Modern--20th century--Exhibitions
Art--Private collections--Germany--Cologne--Exhibitions.
Speck, Reiner--Art collections--Exhibitions.
Princeton subject headings:
Art, Modern--20th century--Exhibitions.
Art--Private collections--Germany--Exhibitions.
Artists' books--Germany--Exhibitions.
Private libraries--Germany--Exhibitions.
Speck, Reiner--Art collections--Exhibitions.
Speck, Reiner--Library--Exhibitions.