New York, 10 July 1939 - Institutional correspondence Blanche Mahler's letter to Grace L. McCann Morley
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
2 May 1939 - Internal institutional documents A draft text for the invitation to the exhibition Picasso's Guernica at the Valentine Gallery, New York