Flushing, New York, 23 May 1939 - Institutional correspondence Simon Guggenheim's and Dana C. Backus's form letter to ask for donations
Montecarlo, 24 August 1979 - Institutional correspondence Letter from Douglas Cooper to Evelio Verdera
Providence, Rhode Island, 12 May 1939 - Institutional correspondence Alexander Dorner's letter to Sidney Janis