New York, April 14, 1967 - Letter Alfred H. Barr Jr.'s letter to Daniel-Henry Kahnweiler, dated 14 April 1967
New York, 14 April 1967 - Institutional correspondence Alfred H. Barr Jr.'s letter to Daniel-Henry Kahnweiler, dated 14 April 1967
New York, April 1967 - Petition A request from Angry Arts to support the withdrawal of Guernica from the Museum of Modern Art, New York
Paris, April 20, 1967 - Letter Daniel-Henry Kahnweiler's letter to Alfred H. Barr Jr., dated 20 April 1967