MICHAEL PHILIPP is Chief Curator at the Museum Barberini, Potsdam, Germany. nNERINA SANTORIUS is Curator and Head of Impressionism at the Museum Barberini, Potsdam, Germany. nORTRUD WESTHEIDER is Director of the Museum Barberini, Potsdam, Germany. nDANIEL ZAMANI is Artistic Director of the Museum Frieder Burda, Baden-Baden, Germany.