1919 painting Proun P23, no. 6 by El Lissitzky

This undated photo provided by Van Abbemuseum in Eindhoven on Tuesday, Oct. 29, 2013, shows the 1919 painting Proun P23, no. 6 by El Lissitzky. Dutch museums have identified in their collections 139 pieces of art, including dozens of paintings, one by Matisse and many by Dutch painters of varying renown such as Impressionist Isaac Israels, likely having been taken forcibly from Jewish owners during the Nazi era. (AP Photo/Van Abbemuseum)