New York, 22 April 1960 - Institutional correspondence A letter from Jan-Albert Goris to Nelson Rockefeller, dated 22 April 1960
New York, 25 April 1960 - Institutional correspondence Jan-Albert Goris's letter to Nelson Rockefeller, dated 25 April 1960
New York, 23 October 1969 - Institutional correspondence Elizabeth Shaw's letter to William S. Lieberman