Lapworth, Phil, author
Sage Publications, 2004
Buku Teks
Jacobs, Michael, author
Open University Press, 2006
Buku Teks
Nelson-Jones, Richard, author
Thousand Oaks, California: SAGE, 2014
Buku Teks
Casemore, Roger
Sage Publications, 2006
Buku Teks
Lister-Ford, Christine, author
Sage Publications, 2002
Buku Teks