Philp, Hugh
Macquarie University, 1984
Buku Teks
Haeussler, Ernest F.
Reston Publishing, 1983
Buku Teks
Atkinson, Brian
Addison - Wesley , 1998
Buku Teks
Hornby, Win
Prentice-Hall, 2001
Buku Teks
James Cook University of North Queensland
James Cook University, 1993
Buku Referensi