New York, April 14, 1967 - Letter Alfred H. Barr Jr.'s letter to Daniel-Henry Kahnweiler, dated 14 April 1967
Paris, April 20, 1967 - Letter Daniel-Henry Kahnweiler's letter to Alfred H. Barr Jr., dated 20 April 1967
New York, February 24, 1970 - Letter A letter from Walter Bareiss and Robert Von Berg to Wilder Green
New York, January 22, 1970 - Letter A letter from the Operating Committee of the Museum of Modern Art, New York, to Joan Snyder