Sim, R.S.
Butterworth, 1984
Buku Teks
Burton, Samuel Holroyd, author
Macmillan, 1995
Buku Teks
Coxon, Rosemary, author
Letts Educational, 1994
Buku Teks
Keenan, Denis, author
Pitman, 1992
Buku Teks
Slapper, Gary, author
Cavendish Publishing Limited, 2000
Buku Teks