Carvan, John
LBC Information Service, 1997
Buku Teks
Woon, Walter C. M., author
Prentice-Hall, 2000
Buku Teks
Holmes, Ann
Cavendish Publishing Limited, 1997
Buku Teks
Sudargo Gautama, author
Citra Aditya Bakti, 2002
Buku Teks
Howell, Rate A., author
The Dryden Press, 1984
Buku Teks