Mexico, 21 December 1939 - Personal correspondence Juan Larrea's letter to Pablo Picasso, dated 21 December 1939
Flushing, New York, 23 May 1939 - Institutional correspondence Simon Guggenheim's and Dana C. Backus's form letter to ask for donations
Mexico, 10 July 1947 - Personal correspondence Juan Larrea's letter to Alfred H. Barr Jr., dated 10 July 1947
Mexico, 4 October 1939 - Personal correspondence Juan Larrea's letter to Pablo Picasso, dated 4 October 1939
Mexico City, 6 September 1947 - Personal correspondence Juan Larrea's letter to Pablo Picasso, dated 6 September 1947