Philadelphia, 18 September 1957 - Institutional correspondence Henry Clifford's letter to Pablo Picasso
Madrid, 22 April 1976 - Internal institutional documents A report by Joaquín de la Puente on the ownership of Guernica and the negotiation possibilities with the Museum of Modern Art, New York
Philadelphia, 1958 - Exhibition catalogue Catalogue for the exhibition Picasso: 75th Anniversary at the Philadelphia Museum of Art
Madrid, 10 September 1981 - Internal museum documents Certificate for the reception of Guernica, and its stretcher and related works