Porteous, J. Douglas
Routledge , 1996
Buku Teks
Amidon, Jane, author
Thames & Hudson, 2001
Buku Teks
Rubenstein, Harvey M.
New York: John Wiley & Sons, 1980
Buku Teks
Marsh, William M., author
John Wiley & Sons, 1998
Buku Teks
Crow, Sylvia
Packard,, 1988
Buku Teks