edited by Basiro Davey, Alastair Gray, Clive Seale
Open University Press, 2001
Buku Teks
Hitchcock, Janice E.
Delmar, 1999
Buku Teks SO
Walters, Vivienne J.
Croom Helm, 1980
Buku Teks
Lundy, Karen Saucier
Jones and Bartlett , 2009
Buku Teks SO
Farmer, R.D.T.
Blackwell, 1977
Buku Teks