Buchanan, James M.
Liberty Fund, Inc., 1999
Buku Referensi
Abraham Lincoln Association; edited by Roy P. Basler
Rutgers University Press, 1953
Buku Teks
The Publications Division , 1883
Buku Referensi
The Publication Division, 1888
Buku Referensi
The Publication Division, 1884
Buku Referensi