1. Ted Curtis Smythe, The Gilded Age Press, 1865–1900 (Westport, Conn.: Praeger, 2003), 204–06.
2. William Murrell, A History of American Graphic Humor, 1865–1938 (New York: Macmiilan, 1938), 135.
3. Charles Press, The Political Cartoon (Rutherford, N.J.: Fairleigh Dickinson University Press, 1981), 281–83.