'Woman Sitting in an Armchair ' was held by the now famous late collector . When he died a treasure trove of more than 1,500 works was uncovered . Latest to be returned belongs to descendants of art dealer Paul Rosenberg . Similar agreement was signed last week for painting by Max Liebermann . Gurlitt 's father helped Jewish sell 'degenerate ' art outside Germany for cash .
'Woman Sitting in an Armchair ' was held by the now famous late collector . When he died a treasure trove of more than 1,500 works was uncovered . Latest to be returned belongs to descendants of art dealer Paul Rosenberg . Similar agreement was signed last week for painting by Max Liebermann . Gurlitt 's father helped Nazis sell 'degenerate ' art outside Germany for cash .