Wang, James C.F.
Prentice-Hall, 1994
Buku Teks
Merriam, Charles E. (Charles Edward)
New York University Press, 1936
Buku Teks
Solomos, John
Routledge, 1995
Buku Teks
Gilpin, Robert
Cambridge University Press, 1981
Buku Teks
Aitkin, Don
Australian National University Press, 1978
Buku Teks