New York, 10 February 1956 - Institutional correspondence A letter from Louise A. Boyer to Petro (Nelly) Van Doesburg
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