New York, 9 September 1981 - Institutional correspondence An internal letter from Richard E. Oldenburg to staff at the Museum of Modern Art, New York
New York, 24 March 1980 - Institutional correspondence A letter from Richard Oldenburg and William Rubin to Javier Tusell
New York, 24 September 1957 - Institutional correspondence Virginia Pearson's letter to Alfred H. Barr Jr.
New York, 5 November 1957 - Institutional correspondence Virginia Pearson's letter to Katharine Kuh, dated 5 November 1957
New York, 20 September 1957 - Institutional correspondence Virginia Pearson's letter to Katharine Kuh, dated 20 September 1957