Waldo Heinrichs, Threshold of War: Franklin D. Roosevelt & American Entry into WWII, Oxford, Oxford University Press, (ISBN0195061683, lire en ligne), 166
(en-US) Arthur Krock, « The Greer Incident and Hitler's Iceland Policy (Published 1941) », The New York Times, (ISSN0362-4331, lire en ligne, consulté le )
jstor.org
Frank Freidel, "FDR vs. Hitler: American Foreign Policy, 1933-1941" Proceedings of the Massachusetts Historical Society Vol. 99 (1987), pp. 25-43 online p. 39
(en-US) Arthur Krock, « The Greer Incident and Hitler's Iceland Policy (Published 1941) », The New York Times, (ISSN0362-4331, lire en ligne, consulté le )
Arthur Krock, « Text of Krock's Talk on War Policy To Columbia College Alumni », New York Times, (lire en ligne)