Columbia subject headings:
Art, European--20th century--Exhibitions.
Artists' preparatory studies--Europe--Exhibitions.
Drawing--Europe--20th century--Exhibitions.
Museum Ludwig. Graphische Sammlung--Exhibitions.
Sculptors--Europe--Exhibitions.
Harvard subject headings:
Artists' preparatory studies--Europe--Exhibitions.
Drawing--19th century--Europe--Exhibitions.
Drawing--20th century--Europe--Exhibitions.
Museum Ludwig. Graphische Sammlung--Exhibitions.
Princeton subject headings:
Artists' preparatory studies--Europe--Exhibitions.
Drawing, European--19th century--Exhibitions.
Drawing, European--20th century--Exhibitions.
Museum Ludwig. Graphische Sammlung--Exhibitions.