Hollywood, 20 July 1939 - Institutional correspondence Marcelene Peterson's letter to Evelyn Ahrend, dated 20 July 1939
Hollywood, 2 September 1939 - Institutional correspondence Marcelene Peterson's letter to Evelyn Ahrend, dated 2 September 1939
Hollywood, 10 November 1939 - Institutional correspondence Marcelene Peterson's letter to Herman F. Reissig
28 February 1974 - Press release and communication The artist Tony Shafrazi has freed Guernica from its chains of ownership and has returned its revolutionary nature