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 SO
Corwin, Edward S.
The Presidency today
New York University Press, 1956
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Legal institutions today and tomorrow
edited by Monrad G. Paulsen
Columbia University Press, 1959
 Buku Teks