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
2 March 1974 - Institutional correspondence A letter from Karl Denim, S. S. Kush and Joshua Jericho in defence of Tony Shafrazi