Kennan, George F., 1904-
Princeton University Press , 1954
Buku Teks
McCormick, James M.
Thomson, 2005
Buku Teks
Herrick, Christopher
Longman, 2003
Buku Teks
Langdon, Robert M.
Littlefield Adams, 1961
Buku Teks
edited by Eugene R. Wittkopt
Martin Press, 1994
Buku Teks