Meudon, 19 November 1955 - Institutional correspondence Nelly Van Doesburg's letter to Louise Boyer, dated 19 November 1955
Meudon, 19 November 1955 - Institutional correspondence Nelly Van Doesburg's letter to Louise Boyer, dated 19 November 1955
Meudon, 29 December 1955 - Institutional correspondence Nelly Van Doesburg's letter to Louise Boyer, dated 29 December 1955
Meudon, 13 February 1956 - Institutional correspondence Petro (Nelly) Van Doesburg's letter Alfred H. Barr Jr.
Saint Louis, 6 April 1940 - Institutional correspondence James B. Musick's letter to Pablo Picasso, dated 6 April 1940
Saint Louis, 16 April 1940 - Institutional correspondence James B. Musick's letter to Pablo Picasso, dated 16 April 1940
New York, 17 June 1957 - Institutional correspondence John Rockefeller's letter to Alfred H. Barr Jr.