New York, 31 July 1947 - Personal correspondence Alfred H. Barr Jr's letter to. a Bertha Slattery Lieberman
ca. 1952–1957 - Internal museum documents Publicity report for the exhibition Studies for Guernica by the Kansas State Teachers College, Pittsburg, addressed to the Travelling Exhibitions Department at the Museum of Modern Art, New York
Paris, 30 May 1947 - Personal correspondence Daniel H. Kahnweiler’s letter to Alfred H. Barr on the symbolism of Picasso’s Guernica