Andrews, Dorine C.
Yourdon Press, 1994
Buku Teks
Mathews, Richard
The Australian National University, 1999
Buku Teks SO
Crochet, Treena
Prentice-Hall, 1999
Buku Teks SO
John Wiley & Sons, 1999
Buku Teks SO
Jeary, Alan
E & FN Spon, 1997
Buku Referensi