ISBN 978-1479328598 ^ Schickel, Richard. D.W. Griffith His Life and Work, 1985. ^ Pener, Degen (29 October 2011). “Drugs, Affairs and Secret Divorces: Inside the Scandalous
Heinz Sauer / Bob Degen, plaza lost and found Heinz Sauer / Bob Degen with Carey Bell, Blues after Sunrise Heinz Sauer / Bob Degen, Ellingtonia Revisited
Nouveau Postcards. Rizzoli, New York 1987, S. 331 f. Margret Zimmermann-Degen: Hans Christiansen. Leben und Werk eines Jugendstilkünstlers. Teil I (Einführung