London, 9 July 1938 - Personal correspondence E. L. T. Mesens' letter to Roland Penrose, dated 9 July 1938
London, 15 September 1938 - Personal correspondence E. L. T. Mesens' letter to Roland Penrose, dated 15 September 1938
ca. 1952–1956 - Internal museum documents Publicity report for the exhibition Studies for Guernica by the School of Fine and Applied Arts, Columbus, Ohio, addressed to the Travelling Exhibitions Department at the Museum of Modern Art, New York
London, 20 August 1938 - Personal correspondence E. L. T. Mesens' letter to Roland Penrose, dated 20 August 1938
London, 31 August 1938 - Personal correspondence E. L. T. Mesens' letter to Roland Penrose, dated 31 August 1938