Tim Dunne
Oxford University Press, 2010
Buku Teks
Griffith, Martin
Routledge, 2002
Buku Teks
edited by Beth A. Simmons and Richard H. Steinberg
Cambridge University Press, 2006
Buku Teks
Deutsch, Karl Wolfgang, 1912-1992
Prentice-Hall, 1988
Buku Teks
edited by William T.R. Fox
Indiana University of Notre Dame Press , 1959
Buku Teks