Hamburg, 30 March 2015 - Photograph Visitors in front of Guernica Redacted (After Picasso's Guernica, 1937) , by Robert Longo
Ellen C. Oppler (ed.), <em>Picasso’s Guernica</em>, New York and London: W. W. Norton & Company, 1988, 236–238 - Essay “How Effective Is Social Protest Art? (Vietnam)”
Siracusa, New York, 15 July 1979 - Institutional correspondence Ellen Oppler's letter to Luisa Kreisberg