30 October 1981 - Institutional correspondence John Koegel's letter to Richard E. Oldenburg, dated 30 October 1981
Madrid, 1981 - Conferences and articles Notes on the installation of Guernica and sketches in the Casón del Buen Retiro
September, 1981 - Management of reproduction rights Memorandum of understanding between the Museum of Modern Art, New York, and Undersigned