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.
6 September 1992 - Newspapers The Reina Sofía presents its Collection and becomes the century's museum of Spanish art