Vale, Lawrence J.
Routledge, 2008
Buku Teks
Collins, James
Cambridge University Press , 2005
Buku Teks
Curtin, Patricia Ann, 1955-
Sage Publications, 2007
Buku Teks
Simul Press, 1976
Buku Teks
Andrew F. Herrmann, editor
Routledge, Taylor & Francis Group, 2017
Buku Teks