New York, 12 March 1956 - Institutional correspondence Bernard Karpel's letter to Willem Sandberg, dated 12 March 1956
New York, 27 November 1956 - Institutional correspondence Bernard Karpel's letter to Willem Sandberg, dated 27 November 1956
<em>The New York Review of Books</em>, New York, May 6, 1971 - Article “Judgment Deferred on Lieutenant Calley”