Valentine, Christine, author
Routledge, 2008
Buku Teks
Gilson, Julie, author
St. Martin`s Press, 2000
Buku Teks
Bruyn, Severyn T., author
The University of Michigan Press, 2000
Buku Teks
Finegan, Edward, author
Cambridge University Press, 2006
Buku Teks
Friedman, Thomas L., author
Penguin Book, 2006
Buku Teks