Mascull, Bill
HarperCollins Pub , 1996
Buku Teks
Mascull, Bill
Harper Collins Pub. , 1995
Buku Teks
Gates, Bill, author
Warner Books, 1999
Buku Teks
edited by Stephen Clarke
Harper Collins, 1995
Buku Referensi
Pass, Chirtopher, author
Erlangga, 1997
Buku Referensi