John H. White Jr., American Locomotives: An Engineering History, 1830-1880 (Baltimore: Johns Hopkins Univ. Press, 1968), 110, 534.
Steven W. Usselman, Regulating Railroad Innovation: Business, Technology, and Politics in America, 1840-1920 (New York: Cambridge Univ. Press, 2002), 61-75.
Payen-Varieras, "Les cadres salaries du Central Pacific Railroad," 147-57.
Adams to S. R. Callaway, Dec. 23, 1885, UP, PO, OC, vol. 33, ser. 2, r. 27
White, American Locomotive, 110, 444-45.
Maury Klein, Union Pacific, vol. 1: Birth of a Railroad 1862-1893 (Garden City, N.Y.: Doubleday, 1983), 525-27.
Usselman, Regulating Railroad Innovation, 10-11, 63, 70-76, 99-101.
Usselman, Regulating Railroad Innovation, 163-87.