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
2 March 1974 - Institutional correspondence A letter from Karl Denim, S. S. Kush and Joshua Jericho in defence of Tony Shafrazi
Old Westbury, New York, 4 May 1977 - Institutional correspondence Emilia Doyaga's letter to Nelson Rockefeller