New York, 8 May 1968 - Institutional correspondence Antonio Serrano's letter to Fernando María Castiella
<em>The New York Times</em>, New York, February 5, 2003, 27 - Article Maureen Dowd, “Powell Without Picasso”
New York, 15 February 1967 - Management of reproduction rights Pearl L. Moeller's letter to Dorothy C. Miller