Hutton, Peter
APA Publications, 1993
Buku Referensi
December, John
Prenhalindo, 1997
Buku Teks SO
Ariswara
Intermedia, 1992
Buku Teks SO
Harold, Elliotte Rusty
IDG Books Worldwide, 1997
Buku Teks SO
Wirapustaka, [date of publication not identified]
Buku Referensi