Keegan, John
Pimlico, 1994
Buku Teks
Belli, Pierin
Oceana Publications Inc, 1964
Buku Teks
Russell, Bertrand, 1872-1970
Routledge, 2001
Buku Teks
Pustay, John S.
The Free Press, 1965
Buku Teks
Parson, Nels A.
Cambridge: Harvard University Press, 1962
Buku Teks