Dine, Janet, author
Blackstone Press, 1998
Buku Referensi
Heaton, Russell, author
Blackstone Press Limited, 1998
Buku Referensi
Chan, Wing Cheong
LexixNexix, 2005
Buku Teks
Breet
Butterworth, 1989
Buku Teks
Schlesinger, Rudolf B.
The Foundation Press, 1950
Buku Teks