Cutts, Geoff
Alfred Waller, [date of publication not identified]
Buku Teks SO
Hawryszkiewycz, Igor Titus
Prentice-Hall, 1998
Buku Teks
Aktas, A. Ziya
A Reston Book Prentice Hall, 1987
Buku Teks SO
Avison, David
McGraw-Hill, 2008
Buku Teks
Davis, Williams
Addison-Wesley, 1983
Buku Teks SO