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
<em>El País</em>, January 21, 2016 - Article “El fiasco de la Bienal de Arte de Sevilla acaba en condena” (The fiasco of the Art Biennial of Seville ends up with a sentence)