Waltz, Kenneth N., author
Little, Brown, 1967
Buku Teks
Kennan, George F., 1904-, author
Princeton University Press , 1954
Buku Teks
edited by Ernest R. May
George-Braziller, 1963
Buku Teks
McCormick, James M., author
Thomson, 2005
Buku Teks
Herrick, Christopher, author
Longman, 2003
Buku Teks