Sao Paulo, 25 March 1985 and Madrid, 2 April 1985 - Institutional correspondence The loan of Guernica denied for Brazil exhibition
Madrid, 15 March 1986 - Institutional correspondence Letter from Alfonso E. Pérez Sánchez to Dionisio Hernández Gil
New York and Madrid, June 1988 - Institutional correspondence Correspondence between William Rubin and Alfonso E. Pérez Sánchez
1988-1989 - Institutional correspondence Correspondence related to the Guernica exhibition project at the Museum Boymans-van Beuningen in Rotterdam
August-September 1990 - Institutional correspondence Correspondence on an exhibition project in Hiroshima
Ellen C. Oppler (ed.), <em>Picasso’s Guernica</em>, New York and London: W. W. Norton & Company, 1988, 236–238 - Essay “How Effective Is Social Protest Art? (Vietnam)”
Siracusa, New York, 15 July 1979 - Institutional correspondence Ellen Oppler's letter to Luisa Kreisberg