Arul Khun (Michael Firewall), author
Momentum , 2007
Buku Teks
Page, Bruce, author
Doubleday & Company, Inc., Garden City,, 1968
Buku Teks
Kaplan, Louis, author
Duke Unipersity Press, 1995
Buku Teks
Major, Mark Imre
Danubian Press, Inc., 1974
Buku Teks
edited by David Coady
Ashage, 2006
Buku Teks