Leopold, Richard W., author
Alfred A. Knopf, 1962
Buku Teks
Fogel, Robert William, author
Johns Hopkins Press, 1964
Buku Teks
McCamy, James L., author
Alfred A. Knopf, 1952
Buku Teks
Kennan, George F., 1904-, author
Princeton University Press , 1954
Buku Teks
McCormick, James M., author
Thomson, 2005
Buku Teks