Carpenter, Catrine
McGraw-Hill, 2004
Buku Teks SO
Wilkes, Angela
[date of publication not identified]
Buku Teks
Coultas, Barbara
Teach Yourself Books, 1990
Buku Teks SO
Bladon, Rachel
Passport Books, [Date of publication not identified]
Buku Teks SO
Aries, Angela
Hodder & Stoughton, 1994
Buku Teks SO