Columbia subject headings:
Art--Collectors and collecting--Germany--Biography.
Art--Private collections--Germany.
Ludwig, Irene--Art collections.
Ludwig, Irene.
Ludwig, Peter, 1925-1996--Art collections.
Ludwig, Peter, 1925-1996.
Harvard subject headings:
Art--Collectors and collecting--Germany--Biography.
Ludwig, Peter, 1925-1996.
Princeton subject headings: