Le Roy, Michael K.
Wadsworth and Cengage Learning, 2013
Buku Teks
Johnson, Janet Buttolph, 1950-
CQ Press, 2012
Buku Teks
edited David Marsh and Gerry Stoker
Macmillan, 1995
Buku Teks
Pennings, Paul
Sage Publications, 1999
Buku Teks
Moten, Abdul Rashid
Thomson, 2006
Buku Teks