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
New York, 5 November 1938 - Institutional correspondence Herman F. Reissig's letter to Julius Perlstein
New York, 1 November 1939 - Institutional correspondence Herman F. Reissig's letter to Marcelene Peterson, dated 1 November 1939
New York, 2 November 1939 - Institutional correspondence Herman F. Reissig's letter to Milton Wichner
New York, 17 November 1939 - Institutional correspondence Herman F. Reissig's letter to Marcelene Peterson, dated 17 November 1939
<em>The New York Times</em>, New York, February 5, 2003, 27 - Article Maureen Dowd, “Powell Without Picasso”