Toronto, 21 July 1939 - Institutional correspondence Phyllis Lane's letter to Evelyn Ahrend, dated 21 July 1939
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
Toronto, 29 July 1939 - Institutional correspondence Phyllis Lane's letter to Evelyn Ahrend, dated 29 July 1939
Toronto, 12 August 1939 - Institutional correspondence Phyllis Lane's letter to Evelyn Ahrend, dated 12 August 1939
Toronto, 14 August 1939 - Institutional correspondence Phyllis Lane's letter to Evelyn Ahrend, dated 14 August 1939
Gerti Fietzek (ed.), Cologne: Buchhandlung Walther König, 2009 - Essay Maria Eichhorn. The Artist's Contract