New York, 6 May 1955 - Institutional correspondence A letter from W.R. Keating & Company International to R. Lerondelle
New York, 23 January 1957 - Transport documents A letter from the vice-president of W. R. Keating & Company to Willem Sandberg
ca. 1960–1964 - Newspapers Press cutting with a photograph of the replica Guernica tapestry and Nelson Rockefeller, along with a brief text on his collection