Matthews, Janet R.
Allyn and Bacon, 1997
Buku Teks
Radley, Alan
Thousand Oaks Sage , 1994
Buku Teks
Trull, Timothy J., 1960-, author
Thomson Wadsworth, 2005
Buku Teks
Gambrill, Eileen, author
John Wiley & Sons, 2012
Buku Teks
Niven, Neil
Churchill Livingstone , 1994
Buku Teks