Longman, 1993
Buku Teks
Palmer, R.R. (Robert Roswell), 1909-2002, author
Princeton University Press, 1964
Buku Teks
Routledge , 1996
Buku Teks
Harvie, Christopher
Routledge , 1994
Buku Teks
Linz, Juan J., author
Johns Hopkins University Press, 1978
Buku Teks