Fogel, Robert William
Railroads and American economic growth : essays in econometrics history
Johns Hopkins Press, 1964
 Buku Teks
Cochran, Thomas C.
Railroad leaders 1845-1890 the business mind in action / Thomas C. Cochran
Russell & Russell, 1966
 Buku Teks
Richardson, Elmo R.
John Palmer Usher : Linchon's secretary of the interior
University of Kansas Press, 1960
 Buku Teks
Corwin, Edward S.
The Presidency today
New York University Press, 1956
 Buku Teks
Corwin, Edward S.
The Constitution and what it means today
Princeton University press, 1958
 Buku Teks