edited by John Baylis and Steve Smith
Oxford University Press, 2006
Buku Teks
John Baylis, Steve Smith, Patricia Owens.
Oxford University Press, 2014
Buku Teks
Reynolds, P.A., author
Longman, 1994
Buku Teks
Couloumbis, Theodore A., author
Prentice-Hall, 1990
Buku Teks
George, Jim, author
Lynne Reinner, 1994
Buku Teks