Columbia subject headings:
Adolf Ahlers AG--Art collections--Exhibitions.
Art, German--20th century--Exhibitions.
Art--Private collections--Germany--Exhibitions.
Expressionism (Art)--Germany--Exhibitions.
Harvard subject headings:
Princeton subject headings:
Art, German--20th century--Exhibitions.
Expressionism (Art)--Germany--Exhibitions.
Sammlung Firmengruppe Ahlers--Art collections--Exhibitions.