G.K. Hall & Company, 1983
Buku Referensi
Abd aziz Abd Jalal, editor
CERT publications Sdn. Bhd., 2011
Buku Teks
Kettell, Brian
John Wiley & Sons, 2010
Buku Teks
Syed Alwi Mohamed Sultan
Cert , 2006
Buku Teks
Syed Alwi Mohamed Sultan
Cert Publication, 2007
Buku Teks