Milan, 4 August 1953 - Institutional correspondence A letter from Fernanda Wittgens to Willem Sandberg, dated 4 August 1953
Milan, 12 August 1953 - Institutional correspondence Fernanda Wittgens' letter to Willem Sandberg, dated 12 August 1953
Milan, 7 October 1953 - Institutional correspondence A letter from Fernanda Wittgens to Willem Sandberg, dated 7 October 1953
April, 1980 (original from 1957) - Magazines The Picasso Summer. He could say the man's name once, in a whisper, to himself
Cleveland, 25 May 1939 - Institutional correspondence William Mathewson Milliken's letter to Sidney Janis
1940 - Internal museum documents Circulating exhibition contract for Picasso: Forty Years of His Art (second edition), between the Museum of Modern Art, New York, and the Cleveland Museum of Art