McCormick, James M.
Thomson, 2005
Buku Teks
Herrick, Christopher
Longman, 2003
Buku Teks
Kennan, George F., 1904-
Princeton University Press , 1954
Buku Teks
Langdon, Robert M.
Littlefield Adams, 1961
Buku Teks
Destler, I.M.
Brooking Institution, 1990
Buku Teks