Heinz-Dietrich Fischer, Erika J. Fischer: Complete Historical Handbook of the Pulitzer Prize System 1917-2000. Walter de Gruyter, 2011, ISBN 3-11-093912-6, S.30 (google.com).
Heinz-Dietrich Fischer, Erika J. Fischer: Editorial Cartoon Awards 1922-1997: From Rollin Kirby and Edmund Duffy to Herbert Block and Paul Conrad. Walter de Gruyter, 1999, S.225 (google.com).