Corbin, John Boyd
Phoenix The Oryx Press, 1981
Buku Teks
Couger, J. Daniel
John Wiley & Sons, 1975
Buku Teks
Digital Equipment Corporation, 1984
Buku Referensi
McLeod, Raymond
Prentice-Hall, 1995
Buku Teks SO
McLeod, Raymond
Macmillan, 1990
Buku Teks SO