Snyder, Charles R., author
Sage , 2007
Buku Teks
Snyder, Charles R., author
Sage, 2015
Buku Teks
John Wiley & Sons, 2004
Buku Teks
Compton, William C., author
Wadsworth and Cengage Learning, 2013
Buku Teks
Hefferon, Kate, author
McGraw-Hill, 2011
Buku Teks