Philips, Alan, author
Chancellor Press, 1993
Buku Referensi
EMAP Publishing,
Majalah, Jurnal, Buletin
Majalah, Jurnal, Buletin
Achmad Tardiyana, author
Gramedia Pustaka Utama , 2005
Buku Teks SO
Shepheard, Paul, author
Massachusetts Institute of Technology, 1995
Buku Teks