Drate, Spencer, author
North Light Books, 1999
Buku Referensi
New York Dava Kan 1998,
Buku Referensi
Donnelly, Daniel, author
Page One Publishing, 2011
Buku Referensi
Rockport publishers, Inc., 2008
Buku Referensi
Dean, Corinna
Rockport Publishers, 2000.
Buku Teks