16 November 1939 - Personal correspondence A letter from Francisco De Troya to Pablo Picasso, dated 16 November 1939
23 November 1939 - Personal correspondence Francisco de Troya's letter to Pablo Picasso, dated 23 November 1939
1 December 1945 - Institutional correspondence Claude Jaeger's letter to Pablo Picasso with an enclosed letter from Celeste Negarville
ca. 1952–1956 - Internal museum documents Publicity report for the exhibition Studies for Guernica by Allegheny College, Meadville, Pennsylvania, addressed to the Travelling Exhibitions Department at the Museum of Modern Art, New York