Meudon, 19 November 1955 - Institutional correspondence Nelly Van Doesburg's letter to Louise Boyer, dated 19 November 1955
New York, 17 July 1968 - Internal museum documents Jean Volkmer's letter to Bates Lowry, dated 17 July 1968
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.
New York, 17 July 1968 - Internal museum documents Jean Volkmer's letter to Bates Lowry, dated 17 July 1968