Cairncross, Liz, author
Routlege, 1997
Buku Teks
Douglas, Anthony, author
Poutrege, 1998
Buku Teks
by Nigel Malin [and others]
Open University Press, 1999
Buku Teks
Hitchcock, Janice E., author
Delmar, 1999
Buku Teks
Harkreader, Helen, author
Saunders , 2007
Buku Teks