Elbert Hubbard (1907). “Little Journeys to the Homes of Great Reformers ...: John Wesley. Henry George. Garibaldi. Richard Cobden. Thomas Paine. John Knox”
Elbert Hubbard (1905). “Little Journeys to Homes of Great Scientists ...: Copernicus. Galileo. Sir Isaac Newton. Humboldt. Sir William Herschel. Charles Darwin”