In the chaotic aftermath of World War II, the American military seized 20 boxes of art from German dealer Hildebrand Gurlitt in Aschbach in December 1945, according to documents located by The Associated Press in the U.S. National Archives in Washington. [...] found in the son's apartment were paintings, drawings, engravings, woodcuts and prints by Henri Matisse, Pablo Picasso, Pierre-Auguste Renoir, Oskar Kokoschka, and leading German artists Dix, Liebermann and Ernst Ludwig Kirchner. Christoph Zuschlag, an art historian at the University of Koblenz, said the American documents indicated U.S.