Blum, Mark
Chronicle Books, 1999
Buku Referensi
Andromedia Oxford, 1994
Buku Teks SO
Zug, George R.
Academic Press, 1993
Buku Teks SO
Rothschild, Bruce M.
Springer, 2012
eBooks
editors, Tim Halliday, Kraig Adler, Christopher O'toole
Grolier International, 1993
Buku Referensi