Page, Benjamin I.
University of Chicago Press, 2006
Buku Teks SO
Kennedy, Robert F., 1925-1968
Harper & Row , 1962
Buku Teks SO
Chang, Richard T.
Sophia University, 1970
Buku Teks SO
Jones, Howard
Franklin Watts, 1985
Buku Teks SO
Ferrell, Robert H.
W.W. Norton, 1959
Buku Teks