New York, 8 May 1968 - Institutional correspondence Antonio Serrano's letter to Fernando María Castiella
29 April 1940 - Internal museum documents Circulating exhibition contract for Picasso: Forty Years of His Art, (second edition), between the Museum of Modern Art, New York, and the Cincinnati Art Museum
<em>Newsweek</em>, New York, March 10, 2015 - Article “Mark Lombardi's Art Was Full of Conspiracies — Now His Death Has Become One”