Halpern, Diane F.
Lawrence Erlbaum Associates, Publishers, 1996
Buku Teks SO
Mingers, John
Springer, 2006
Buku Teks SO
Mingers, John
Springer, 2006
Buku Teks SO
Koh, Tommy
Asia-Europa Foundation, 2001
Buku Teks SO
Lurie, Morris
Penguin Books, 1985.
Buku Teks SO