New York, 30 May 1957 - Institutional correspondence Alfred H. Barr Jr.'s letter to Daniel-Henry Kahnweiler, dated 30 May 1957
New York, 16 February 1957 - Institutional correspondence Alfred H. Barr Jr.'s letter to Pablo Picasso, dated 16 February 1957
New York, 15 April 1957 - Institutional correspondence Alfred H. Barr Jr.'s letter to Daniel-Henry Kahnweiler, dated 15 April 1957
New York, 27 February 1956 - Institutional correspondence Alfred H. Barr Jr.'s letter to Daniel-Henry Kahnweiler, dated 27 February 1956