New York, 16 October 1981 - Institutional correspondence John Koegel's letter to Javier Tusell, dated 16 October 1981
New York, 16 October 1981 - Institutional correspondence John Koegel's letter to Javier Tusell, dated 16 October 1981
New York, 16 October 1981 - Institutional correspondence John Koegel's letter to Javier Tusell, dated 16 October 1981
30 October 1981 - Institutional correspondence John Koegel's letter to Richard E. Oldenburg, dated 30 October 1981
Hollywood, 21 October 1939 - Institutional correspondence H. Heyman's and G. E. Scheyer's letter to Sidney Janis
Princeton, 8 December 1956 - Institutional correspondence A letter from Kazuko Higuchi to Alfred H. Barr Jr.
New York, 31 August 1981 - Institutional correspondence John Koegel's letter to Richard E. Oldenburg, dated 31 August 1981