The only book that is really important is Miss Ida M.Tarbell's "History of the Standard Oil Company," 2 vols.

(new edition 1911).

Of other popular volumes the present writer has found most useful Herbert N.Casson's "Romance of Steel" (1907), "History of the Telephone" (1910), and "Cyrus Hall McCormick: His Life and Work" (1909); J.H.
Bridge's "Inside History of the Carnegie Steel Company" (1903); "Henry Ford's Own Story" as told to Rose Wildes Lane (1917).
For Chapter V, the author has drawn from articles contributed by him in 1907-8 to "McClure's Magazine" on "Great American Fortunes and their Making;" and for Chapter IV, from an article contributed to the same magazine in 1914, on "Telephones for the Millions.".