Dee, Jonathan, author
Caxton Publishing Group, 2000
Buku Referensi
Skinner, Stephen, author
Parragon, 1997
Buku Referensi
Alexander, Skye
Interaksara, 2004
Buku Teks
Lip, Evelyn, author
Times Books International , 1995
Buku Teks
Dy, Victor L., author
Elex Media Komputindo, 1997
Buku Teks