Johnson, John M., author
The Free Press, 1975
Buku Teks
Watts, Simon, author
Sage, 2013
Buku Teks
Barker, Chris, author
John Wiley & Sons, 1994
Buku Teks
Silverman, David, author
Sage Publications , 2010
Buku Teks
Gaultney, Jane F., author
California, 2007
Buku Teks