Paris, 29 September 1955 - Institutional correspondence Daniel-Henry Kahnweiler's letter to Willem Sandberg, dated 29 September 1955
Paris, 29 September 1955 - Institutional correspondence Daniel-Henry Kahnweiler's letter to Robert Giron
Zurich, 12 December 1955 - Institutional correspondence A letter from Klaus Herdeg to Willem Sandberg
Paris, September 7, 1955 - Personal correspondence Daniel-Henry Kahnweiler's letter to Pablo Picasso, dated September 7, 1955