Gould, Nick, author
Routledge, 2016
Buku Teks
Golightley, Malcom, author
Learning matters Ltd., 2008
Buku Teks
Karban, Kate, author
UK Polity Press, 2011
Buku Teks
Pritchard, Colin, author
Routledge, 2006
Buku Teks
edited by Jerrold R. Brandell
Free Press, 1997
Buku Teks