Gerhard Richter : abstraction - Westheider, Ortrud; Philipp, Michael; Elger, Dietmar; Hortolani, Valerie; Westheider, Ortrud; Bretz, Janice; Butin, Hubertus; Elger, Dietmar; Hortolani, Valerie; Krüger, Matthias; Zweite, Armin (A publication series by the Museum Barberini, 2018)