Asfahl, C. Ray
Pearson/Prentice Hall, 2004
Buku Teks SO
Colling, David A., 1935-
Prentice-Hall, 1990
Buku Teks
Reese, Charles D.
CRC Press, Taylor & Francis Group, 2009
Buku Referensi
Reese, Charles D.
CRC Press, Taylor & Francis Group, 2009
Buku Referensi
Griffith, Alan
Longman, 2000
Buku Teks