New York, 9 September 1981 - Institutional correspondence An internal letter from Richard E. Oldenburg to staff at the Museum of Modern Art, New York
Minneapolis, 18 January 1962 - Institutional correspondence Wayne W. Andersen's letter to Nelson Rockefeller
New York, 24 March 1980 - Institutional correspondence A letter from Richard Oldenburg and William Rubin to Javier Tusell