Evera, Stephen van, author
Cornell University Press, 1997
Buku Teks
edited David Marsh and Gerry Stoker
Macmillan, 1995
Buku Teks
Baglione, Lisa A., author
Thomson Wadsworth, 2007
Buku Teks
Kalvelage, Carl, author
Foresman, 1976
Buku Teks
Johnson, Janet Buttolph, 1950-, author
CQ Press, 2012
Buku Teks