Landis, Dylan, author
PBC International, 1996
Buku Referensi
Craffi, Stephen
Image Publishing, 2002
Buku Teks
Mack, Lorie
Conran Octopus, 1998
Buku Teks
editor, Paco Asensio.
Harper Collins, 2003.
Buku Teks
Sommer, Robert, author
Prentice-Hall, 1969
Buku Teks