Benge, Sophie
Periplus Editions (HK) Ltd., 1999
Buku Referensi
Leigh, Michelle Dominique
Thorsons, 1994
Buku Teks SO
Inglis, Kim
Tuttle Publishing, 2009
Buku Teks SO
Campsie, Jane
Murdoch, 1997
Buku Teks SO
Daniel, F.
Oxford University Press, 1969
Buku Teks SO