Mansfield, Peter, author
Optima , 1995
Buku Teks
Harvey, Clare G., author
Thorsons, 1995
Buku Referensi
Barnard, Julian, author
Ashgrove Press, 1988
Buku Referensi
Wilwood, Chrissie, author
Piatkuss, 1998
Buku Teks
Harris, Donald, author
Cambridge University Press, 2005
Buku Teks